Merge master.

2026-01-26 15:28:27 -05:00 · 2018-07-24 13:51:52 -04:00
parent f2e54a70f0 107ec432e5
commit b61ade47fc
12 changed files with 816 additions and 149 deletions
--- a/atom.sh
+++ b/atom.sh
@@ -79,14 +79,20 @@ if [ $OS == 'Mac' ]; then
    ATOM_APP_NAME="$(basename "$ATOM_APP")"
  fi

-  if [ "$CHANNEL" == 'beta' ]; then
-    ATOM_EXECUTABLE_NAME="Atom Beta"
-  elif [ "$CHANNEL" == 'nightly' ]; then
-    ATOM_EXECUTABLE_NAME="Atom Nightly"
-  elif [ "$CHANNEL" == 'dev' ]; then
-    ATOM_EXECUTABLE_NAME="Atom Dev"
+  if [ ! -z "${ATOM_APP_NAME}" ]; then
+    # If ATOM_APP_NAME is known, use it as the executable name
+    ATOM_EXECUTABLE_NAME="${ATOM_APP_NAME%.*}"
  else
-    ATOM_EXECUTABLE_NAME="Atom"
+    # Else choose it from the inferred channel name
+    if [ "$CHANNEL" == 'beta' ]; then
+      ATOM_EXECUTABLE_NAME="Atom Beta"
+    elif [ "$CHANNEL" == 'nightly' ]; then
+      ATOM_EXECUTABLE_NAME="Atom Nightly"
+    elif [ "$CHANNEL" == 'dev' ]; then
+      ATOM_EXECUTABLE_NAME="Atom Dev"
+    else
+      ATOM_EXECUTABLE_NAME="Atom"
+    fi
  fi

  if [ -z "${ATOM_PATH}" ]; then
--- a/docs/rfcs/003-consolidate-core-packages.md
+++ b/docs/rfcs/003-consolidate-core-packages.md
@@ -0,0 +1,345 @@
+# Consolidate Core Atom Packages
+
+## Status
+
+Accepted
+
+## Summary
+
+Atom's official distribution is comprised of 92 core packages which provide its built-in functionality.  These packages currently live in their own independent repositories in the Atom organization, all with their own separate issues, PRs, releases, and CI configurations.  This RFC proposes that by consolidating most, if not all, of these core packages back into the `atom/atom` repo, we will see the following benefits:
+
+- Less confusion for new contributors
+- Simpler core package contribution experience
+- Greatly reduced burden for maintainers
+
+## Motivation
+
+Let's cover each of the bullet points mentioned above:
+
+### Less confusion for contributors
+
+Imagine that a new contributor wants to add a small new feature to the `tree-view` package.  The first place they are likely to look is the `atom/atom` repository.  Scanning through the folders will lead to a dead end as nothing that looks like `tree-view` code can be found.  They might take one of the following steps next:
+
+- By reading README.md, maybe they will decide to click the link to the Atom Flight Manual and _maybe_ find the [Contributing to Official Atom Packages](https://flight-manual.atom.io/hacking-atom/sections/contributing-to-official-atom-packages/) page there
+- They could read the CONTRIBUTING.md file which [has a section](https://github.com/atom/atom/blob/master/CONTRIBUTING.md#atom-and-packages) that explains where to find the repos for core packages and how to contribute, but we don't really have a clear pointer to that in our README.md
+- If they don't happen to find that page, they might use Google to search for "atom tree view" and find the atom/tree-view repo and _maybe_ read the CONTRIBUTING.md file which sends them to Atom's overall contribution documentation
+- They might go to the Atom Forum or Slack community to ask how to contribute to a particular part of Atom and *hopefully* get a helpful response that points them in the right direction
+
+Having all of the core Atom packages represented in a top-level `packages` folder, even if they all don't actually live in the repo, will go a long way to making the core package code more discoverable.
+
+### Simpler core package contribution experience
+
+Separating core Atom features out into individual repositories and delivering them to Atom builds via `apm` is a great idea in theory because it validates the Atom package ecosystem and gives developers many examples of how to develop an Atom package.  It also gives Atom developers real-world experience working with Atom's APIs so that we ensure community package authors have the same hackability that Atom developers enjoy.
+
+On the other hand, having these packages live in separate repositories and released "independently" introduces a great deal of overhead when adding new features.  Here is a comparison of the current package development workflow contrasted to what we could achieve with consolidated packages:
+
+#### Current Package Development Workflow
+
+For example, to add a single feature to the `tree-view` package, one must:
+
+1. Fork and clone the `tree-view` repository to their computer (making sure to pull the commit relevant to the version of Atom they are working with)
+1. Run `apm install` and `apm link` inside of the repo folder
+1. Make their desired changes to the code
+1. Open a PR to the `tree-view` repo and wait for CI to pass and a maintainer to review it
+1. Work with maintainers to get the PR approved and merged
+
+After this is finished, an Atom maintainer must take the following steps:
+
+1. Clone the `tree-view` repo
+2. Run `apm publish` to publish a new release of the package
+3. Edit `package.json` in the Atom repo to reflect the new version of `tree-view`
+4. Commit and push the changes to the relevant branch where the change belongs (`master` or `1.nn-releases`)
+
+#### Simplified Package Development
+
+If we were to move `tree-view` (or any other core Atom package) back into `atom/atom`, the development workflow would look more like this:
+
+1. Fork and clone `atom/atom` and switch to a release branch if necessary
+1. Build Atom and launch it in dev mode
+1. Make desired changes to the code in `packages/tree-view`
+1. Open a PR on `atom/atom` and wait for CI to pass and a maintainer to review it
+1. Work with maintainers to get the PR approved and merged
+
+At this point, the change is merged into Atom and ready for inclusion in the next release.
+
+### Greatly reduced burden for maintainers
+
+Since packages all have their own repositories, this means that we have to watch 91 different repos for issues and pull requests.  This also means that we have to redirect issues filed on `atom/atom` to the appropriate repository when a user doesn't know where it belongs.  Even more importantly, there's not an easy way to prioritize and track issues across the Atom organization without using GitHub Projects.
+
+Also, as mentioned above, there's the added duty of doing the package "version dance" when we merge any new PRs to a package repository: publish the package update, update `package.json` in Atom.  It's very easy to forget to do this and not have community contributions included in the next Atom release!
+
+The more core packages live in `atom/atom`, the less work Atom maintainers have to do overall.
+
+## Explanation
+
+Many of Atom's core packages now live in the core `atom/atom` repository.  To the Atom user, this change will be imperceptible as these packages still show up in the list of Core Packages in the Settings View.  Users can still optionally disable these packages.
+
+For maintainers and contributors, there will be less juggling of repositories and no more publishing of updates to these packages with `apm`:
+
+Contributors now clone and build `atom/atom` to work on improvements to core packages.  They will no longer have to use `apm link` in dev mode to test changes they make to packages in the repo's `packages` folder.  Core packages that aren't consolidated still have folders under `packages` with README.md files that point to the home repository for that package.
+
+When a contributor sends a PR to `atom/atom` that only affects files in a folder under `packages`, only the specs for the relevant package folders will be executed using Atom's CI scripts.  This means that a full Atom build will not be required when no Atom Core code is changed in a PR.  Package specs are also now run against all 3 OSes on Atom `master` and release builds.
+
+Atom maintainers no longer have to publish new versions to consolidated core packages and then edit `package.json` to bump the package version in a particular Atom release branch (Stable, Beta, or `master`).  When a PR against a consolidated core package in `atom/atom` is merged, no version number change is required and the changes will immediately be a part of the next release from that branch.
+
+## Drawbacks
+
+One possible drawback of this approach is that there might be some initial confusion where core Atom packages live, especially if some are consolidated into `atom/atom` and others still live in their own repositories.  We will manage this confusion by doing the following:
+
+- Include a `README.md` file in the `packages` folder which lists core packages that are not consolidated in the Atom repo.  This will enable users to find the home repositories of those packages.
+
+- Archive the repositories for consolidated core packages, but only after migrating existing issues, merging or closing existing PRs, and updating the README.md to point to the new home of the package code.
+
+Also, contributors will now have to fork, clone, and build `atom/atom` to contribute to core packages where they would previously just need to clone the package repository.  This might put added burden on them such as installing necessary build dependencies on their machine that they wouldn't otherwise need.  It is very likely we could simplify this process for them, though.
+
+One final drawback is that it will now be harder to have single-package maintainers. We currently have 7 core packages where there is a maintainer who isn't a part of the core Atom maintainers team.  These maintainers generally are able to merge community PRs and make commits to those packages with their own judgement.  If we get rid of individual package repositories, do we now make those maintainers full Atom maintainers?
+
+## Rationale and alternatives
+
+The Motivation section explains most of the rationale, so this section will focus on the process of consolidating packages back into `atom/atom`. The set of packages we've chosen to consolidate were evaluated based on a few factors:
+
+- Number of open issues and PRs (exclude any with > 10 open PRs)
+- Time since last update (longer duration since last update is prioritized)
+- Number of package-only maintainers on the repo (exclude any with package maintainers for now)
+
+Using this criteria, all 91 packages have been evaluated and categorized to determine whether they are good candidates for consolidation:
+
+#### Initial Consolidation Candidates
+
+| Package | Open Issues | Open PRs | Outside Maintainers | Last Updated |
+|---------|-------------|----------|---------------------| -------------|
+| **[about]** | 2 | 0 | 0 | 7/11/18 |
+| **[archive-view]** | 10 | 0 | 0 | 6/3/18 |
+| **[atom-dark-syntax]** | 5 | 0 | 0 | 12/6/17 |
+| **[atom-dark-ui]** | 1 | 2 | 0 | 2/13/18 |
+| **[atom-light-syntax]** | 1 | 0 | 0 | 10/17/16 |
+| **[atom-light-ui]** | 1 | 0 | 0 | 2/13/18 |
+| **[autoflow]** | 17 | 4 | 0 | 4/17/18 |
+| **[autosave]** | 13 | 0 | 0 | 9/16/17 |
+| **[background-tips]** | 3 | 2 | 0 | 2/17/18 |
+| **[base16-tomorrow-dark-theme]** | 5 | 0 | 0 | 1/10/17 |
+| **[base16-tomorrow-light-theme]** | 1 | 0 | 0 | 1/10/17 |
+| **[bookmarks]** | 19 | 4 | 0 | 12/10/17 |
+| **[bracket-matcher]** | 74 | 8 | 0 | 3/20/18 |
+| **[command-palette]** | 18 | 6 | 0 | 2/27/18 |
+| **[dalek]** | 2 | 0 | 0 | 2/28/18 |
+| **[deprecation-cop]** | 5 | 0 | 0 | 9/7/17 |
+| **[dev-live-reload]** | 4 | 0 | 0 | 11/14/17 |
+| **[encoding-selector]** | 11 | 2 | 0 | 4/19/18 |
+| **[exception-reporting]** | 5 | 0 | 0 | 2/6/18 |
+| **[git-diff]** | 38 | 1 | 0 | 1/18/18 |
+| **[go-to-line]** | 5 | 2 | 0 | 1/25/18 |
+| **[grammar-selector]** | 3 | 1 | 0 | 4/12/18 |
+| **[image-view]** | 4 | 4 | 0 | 7/9/18 |
+| **[incompatible-packages]** | 1 | 0 | 0 | 4/25/17 |
+| **[keybinding-resolver]** | 11 | 3 | 0 | 7/6/18 |
+| **[language-clojure]** | 13 | 3 | 0 | 1/26/18 |
+| **[language-coffee-script]** | 9 | 2 | 0 | 11/1/17 |
+| **[language-csharp]** | 1 | 1 | 0 | 4/27/18 |
+| **[language-css]** | 6 | 7 | 0 | 6/11/18 |
+| **[language-gfm]** | 52 | 9 | 0 | 6/15/18 |
+| **[language-git]** | 4 | 2 | 0 | 4/18/17 |
+| **[language-html]** | 11 | 4 | 0 | 7/5/18 |
+| **[language-hyperlink]** | 2 | 3 | 0 | 10/25/17 |
+| **[language-json]** | 1 | 0 | 0 | 5/11/18 |
+| **[language-less]** | 5 | 1 | 0 | 6/11/18 |
+| **[language-make]** | 7 | 3 | 0 | 11/26/16 |
+| **[language-mustache]** | 0 | 0 | 0 | 2/5/18 |
+| **[language-objective-c]** | 2 | 0 | 0 | 12/1/15 |
+| **[language-php]** | 25 | 7 | 0 | 6/11/18 |
+| **[language-property-list]** | 1 | 0 | 0 | 3/11/17 |
+| **[language-python]** | 33 | 4 | 0 | 6/18/18 |
+| **[language-ruby]** | 38 | 10 | 0 | 10/25/17 |
+| **[language-ruby-on-rails]** | 9 | 6 | 0 | 12/7/17 |
+| **[language-sass]** | 12 | 5 | 0 | 5/2/18 |
+| **[language-shellscript]** | 12 | 3 | 0 | 6/18/18 |
+| **[language-source]** | 0 | 0 | 0 | 1/6/15 |
+| **[language-sql]** | 6 | 4 | 0 | 1/26/18 |
+| **[language-text]** | 1 | 0 | 0 | 3/9/18 |
+| **[language-todo]** | 10 | 6 | 0 | 1/26/18 |
+| **[language-toml]** | 1 | 0 | 0 | 1/6/18 |
+| **[language-typescript]** | 6 | 0 | 0 | 6/18/18 |
+| **[language-xml]** | 2 | 1 | 0 | 6/12/17 |
+| **[language-yaml]** | 8 | 2 | 0 | 3/9/18 |
+| **[line-ending-selector]** | 10 | 0 | 0 | 5/18/18 |
+| **[link]** | 0 | 1 | 0 | 11/14/17 |
+| **[metrics]** | 1 | 2 | 0 | 7/5/18 |
+| **[notifications]** | 29 | 8 | 0 | 3/22/18 |
+| **[one-dark-syntax]** | 4 | 0 | 0 | 5/27/18 |
+| **[one-dark-ui]** | 13 | 1 | 0 | 5/1/18 |
+| **[one-light-syntax]** | 2 | 1 | 0 | 5/27/18 |
+| **[one-light-ui]** | 2 | 0 | 0 | 5/1/18 |
+| **[open-on-github]** | 8 | 3 | 0 | 11/21/17 |
+| **[package-generator]** | 10 | 2 | 0 | 11/16/17 |
+| **[status-bar]** | 25 | 3 | 0 | 11/6/17 |
+| **[styleguide]** | 12 | 2 | 0 | 4/12/18 |
+| **[tabs]** | 66 | 7 | 0 | 5/13/18 |
+| **[timecop]** | 5 | 0 | 0 | 11/4/17 |
+| **[update-package-dependencies]** | 0 | 0 | 0 | 12/10/17 |
+| **[welcome]** | 0 | 0 | 0 | 11/21/17 |
+| **[whitespace]** | 31 | 6 | 0 | 5/30/18 |
+| **[wrap-guide]** | 3 | 4 | 0 | 11/27/17 |
+
+#### Packages to be Consolidated Later
+
+The following packages will not be consolidated until the stated reasons can be resolved or we decide on a consolidation strategy for them:
+
+| Package | Open Issues | Open PRs | Outside Maintainers | Last Updated | Reason |
+|---------|-------------|----------|---------------------|--------------|-------|
+| **[find-and-replace]** | 219 | 17 | 0 | 6/4/18 | Too many open PRs |
+| **[fuzzy-finder]** | 89 | 22 | 0 | 5/17/18 | Too many open PRs |
+| **[github]** |  |  |  |  | Independent project |
+| **[language-c]** | 53 | 15 | 0 | 7/10/18 | Too many open PRs |
+| **[language-go]** | 12 | 2 | **1** | 6/18/18 | Package maintainer, possibly inactive? |
+| **[language-java]** | 8 | 2 | **1** | 6/11/18 | Package maintainer |
+| **[language-javascript]** | 66 | 12 | 0 | 7/6/18 | Too many open PRs |
+| **[language-perl]** | 17 | 1 | **1** | 10/30/17 | Package maintainer, possibly inactive? |
+| **[markdown-preview]** | 139 | 12 | 0 | 1/8/18 | Too many open PRs |
+| **[settings-view]** | 137 | 18 | 0 | 5/17/18 | Too many open PRs |
+| **[snippets]** | 57 | 4 | **1** | 4/17/18 | Package maintainer |
+| **[solarized-dark-syntax]** | 8 | 3 | **1** | 5/27/18 | Package maintainer |
+| **[solarized-light-syntax]** | 2 | 3 | **1** | 5/27/18 | Package maintainer |
+| **[spell-check]** | 68 | 14 | **1** | 5/25/18 | Too many open PRs, package maintainer |
+| **[symbols-view]** | 86 | 13 | 0 | 12/10/17 | Too many open PRs |
+| **[tree-view]** | 210 | 36 | 0 | 3/21/18 | Too many open PRs |
+
+#### Packages to Never Consolidate
+
+These packages will not be consolidated because they would inhibit contributions from our friends in the Nuclide team at Facebook:
+
+- **[autocomplete-atom-api]**
+- **[autocomplete-css]**
+- **[autocomplete-html]**
+- **[autocomplete-plus]**
+- **[autocomplete-snippets]**
+
+### Consolidation Process
+
+To consolidate a single core package repository back into `atom/atom`, the following steps will be taken:
+
+1. All open pull requests on the package's repository must either be closed or merged before consolidation can proceed
+1. The package repository's code in `master` will be copied over to Atom's `packages` folder in a subfolder bearing that package's name.
+1. Atom's `package.json` file will be updated to change the package's `packageDependencies` entry to reference its local path with the following syntax: `"tree-view": "file:./packages/tree-view"`
+1. A test build will be created locally to manually verify that the package loads and works correctly at first glance
+1. The package specs for the newly-consolidated package will be run against the local Atom build
+1. A PR will be sent to `atom/atom` to verify that CI passes with the introduction of the consolidated package
+1. Once CI is clean and the PR is approved, the PR will be merged
+1. The package's original repository will have all of its existing issues moved over to `atom/atom` using a bulk issue mover tool, assigning a label to those issues relative to the package name, like `packages/tree-view`
+1. The package's original repository will have its README.md updated to point contributors to the code's new home in `atom/atom`
+1. The package's original repository will now be archived on GitHub
+
+### Alternative Approaches
+
+One alternative approach would be to break this core Atom functionality out of packages and put it directly in the Atom codebase without treating them as packages.  This would simplify the development process even further but with the following drawbacks:
+
+- The Atom team would have less regular exposure to Atom package development
+- Users would no longer be able to disable core packages to replace their behavior with other packages (different tree views, etc)
+
+## Unresolved questions
+
+- Is there a good reason to not move the `language-*` packages into `atom/atom`?
+
+  One concern here is that there exist projects which depend directly on these repositories for the TextMate syntax grammars they contain.  Moving the code into `atom/atom` would require that we notify the consumers of the grammars so that they can redirect their requests to the `atom/atom` repo.
+
+- Should we use `git subtree` to migrate the entire commit history of these packages over or just depend on the history from a package's original repository?
+
+  For now, we won't use `git subtree` due to the possibility that bringing over thousands of commits could cause unknown problems in the Atom repo.  We may try this for newly consolidated packages in the future if we decide that not having the package commit history is a sufficient impediment to problem investigations.
+
+- What are the criteria we might use to eventually decide to move larger packages like `tree-view`, `settings-view`, and `find-and-replace` back into `atom/atom`?
+
+- Will we be losing any useful data about these packages if we don't have standalone repositories anymore?
+
+- Should we use this as an opportunity to remove any unnecessary packages from the core Atom distribution?
+
+[about]: https://github.com/atom/about
+[archive-view]: https://github.com/atom/archive-view
+[atom-dark-syntax]: https://github.com/atom/atom-dark-syntax
+[atom-dark-ui]: https://github.com/atom/atom-dark-ui
+[atom-light-syntax]: https://github.com/atom/atom-light-syntax
+[atom-light-ui]: https://github.com/atom/atom-light-ui
+[autocomplete-atom-api]: https://github.com/atom/autocomplete-atom-api
+[autocomplete-css]: https://github.com/atom/autocomplete-css
+[autocomplete-html]: https://github.com/atom/autocomplete-html
+[autocomplete-plus]: https://github.com/atom/autocomplete-plus
+[autocomplete-snippets]: https://github.com/atom/autocomplete-snippets
+[autoflow]: https://github.com/atom/autoflow
+[autosave]: https://github.com/atom/autosave
+[background-tips]: https://github.com/atom/background-tips
+[base16-tomorrow-dark-theme]: https://github.com/atom/base16-tomorrow-dark-theme
+[base16-tomorrow-light-theme]: https://github.com/atom/base16-tomorrow-light-theme
+[bookmarks]: https://github.com/atom/bookmarks
+[bracket-matcher]: https://github.com/atom/bracket-matcher
+[command-palette]: https://github.com/atom/command-palette
+[dalek]: https://github.com/atom/dalek
+[deprecation-cop]: https://github.com/atom/deprecation-cop
+[dev-live-reload]: https://github.com/atom/dev-live-reload
+[encoding-selector]: https://github.com/atom/encoding-selector
+[exception-reporting]: https://github.com/atom/exception-reporting
+[find-and-replace]: https://github.com/atom/find-and-replace
+[fuzzy-finder]: https://github.com/atom/fuzzy-finder
+[git-diff]: https://github.com/atom/git-diff
+[github]: https://github.com/atom/github
+[go-to-line]: https://github.com/atom/go-to-line
+[grammar-selector]: https://github.com/atom/grammar-selector
+[image-view]: https://github.com/atom/image-view
+[incompatible-packages]: https://github.com/atom/incompatible-packages
+[keybinding-resolver]: https://github.com/atom/keybinding-resolver
+[language-c]: https://github.com/atom/language-c
+[language-clojure]: https://github.com/atom/language-clojure
+[language-coffee-script]: https://github.com/atom/language-coffee-script
+[language-csharp]: https://github.com/atom/language-csharp
+[language-css]: https://github.com/atom/language-css
+[language-gfm]: https://github.com/atom/language-gfm
+[language-git]: https://github.com/atom/language-git
+[language-go]: https://github.com/atom/language-go
+[language-html]: https://github.com/atom/language-html
+[language-hyperlink]: https://github.com/atom/language-hyperlink
+[language-java]: https://github.com/atom/language-java
+[language-javascript]: https://github.com/atom/language-javascript
+[language-json]: https://github.com/atom/language-json
+[language-less]: https://github.com/atom/language-less
+[language-make]: https://github.com/atom/language-make
+[language-mustache]: https://github.com/atom/language-mustache
+[language-objective-c]: https://github.com/atom/language-objective-c
+[language-perl]: https://github.com/atom/language-perl
+[language-php]: https://github.com/atom/language-php
+[language-property-list]: https://github.com/atom/language-property-list
+[language-python]: https://github.com/atom/language-python
+[language-ruby]: https://github.com/atom/language-ruby
+[language-ruby-on-rails]: https://github.com/atom/language-ruby-on-rails
+[language-sass]: https://github.com/atom/language-sass
+[language-shellscript]: https://github.com/atom/language-shellscript
+[language-source]: https://github.com/atom/language-source
+[language-sql]: https://github.com/atom/language-sql
+[language-text]: https://github.com/atom/language-text
+[language-todo]: https://github.com/atom/language-todo
+[language-toml]: https://github.com/atom/language-toml
+[language-typescript]: https://github.com/atom/language-typescript
+[language-xml]: https://github.com/atom/language-xml
+[language-yaml]: https://github.com/atom/language-yaml
+[line-ending-selector]: https://github.com/atom/line-ending-selector
+[link]: https://github.com/atom/link
+[markdown-preview]: https://github.com/atom/markdown-preview
+[metrics]: https://github.com/atom/metrics
+[notifications]: https://github.com/atom/notifications
+[one-dark-syntax]: https://github.com/atom/one-dark-syntax
+[one-dark-ui]: https://github.com/atom/one-dark-ui
+[one-light-syntax]: https://github.com/atom/one-light-syntax
+[one-light-ui]: https://github.com/atom/one-light-ui
+[open-on-github]: https://github.com/atom/open-on-github
+[package-generator]: https://github.com/atom/package-generator
+[settings-view]: https://github.com/atom/settings-view
+[snippets]: https://github.com/atom/snippets
+[solarized-dark-syntax]: https://github.com/atom/solarized-dark-syntax
+[solarized-light-syntax]: https://github.com/atom/solarized-light-syntax
+[spell-check]: https://github.com/atom/spell-check
+[status-bar]: https://github.com/atom/status-bar
+[styleguide]: https://github.com/atom/styleguide
+[symbols-view]: https://github.com/atom/symbols-view
+[tabs]: https://github.com/atom/tabs
+[timecop]: https://github.com/atom/timecop
+[tree-view]: https://github.com/atom/tree-view
+[update-package-dependencies]: https://github.com/atom/update-package-dependencies
+[welcome]: https://github.com/atom/welcome
+[whitespace]: https://github.com/atom/whitespace
+[wrap-guide]: https://github.com/atom/wrap-guide
--- a/package.json
+++ b/package.json
@@ -72,7 +72,7 @@
    "sinon": "1.17.4",
    "temp": "^0.8.3",
    "text-buffer": "13.14.5",
-    "tree-sitter": "0.12.20",
+    "tree-sitter": "0.13.0",
    "typescript-simple": "1.0.0",
    "underscore-plus": "^1.6.8",
    "winreg": "^1.2.1",
@@ -85,10 +85,10 @@
    "atom-light-ui": "0.46.2",
    "base16-tomorrow-dark-theme": "1.5.0",
    "base16-tomorrow-light-theme": "1.5.0",
-    "one-dark-ui": "1.12.3",
-    "one-light-ui": "1.12.3",
-    "one-dark-syntax": "1.8.3",
-    "one-light-syntax": "1.8.3",
+    "one-dark-ui": "1.12.4",
+    "one-light-ui": "1.12.4",
+    "one-dark-syntax": "1.8.4",
+    "one-light-syntax": "1.8.4",
    "solarized-dark-syntax": "1.1.5",
    "solarized-light-syntax": "1.1.5",
    "about": "1.10.0",
@@ -121,7 +121,7 @@
    "line-ending-selector": "0.7.7",
    "link": "0.31.4",
    "markdown-preview": "0.159.20",
-    "metrics": "1.5.0",
+    "metrics": "1.6.0",
    "notifications": "0.70.5",
    "open-on-github": "1.3.1",
    "package-generator": "1.3.0",
@@ -138,18 +138,18 @@
    "welcome": "0.36.6",
    "whitespace": "0.37.6",
    "wrap-guide": "0.40.3",
-    "language-c": "0.59.11",
+    "language-c": "0.60.0",
    "language-clojure": "0.22.7",
    "language-coffee-script": "0.49.3",
    "language-csharp": "1.0.4",
    "language-css": "0.42.11",
    "language-gfm": "0.90.5",
    "language-git": "0.19.1",
-    "language-go": "0.45.4",
-    "language-html": "0.50.3",
+    "language-go": "0.46.0",
+    "language-html": "0.51.1",
    "language-hyperlink": "0.16.3",
    "language-java": "0.30.0",
-    "language-javascript": "0.128.11",
+    "language-javascript": "0.129.1",
    "language-json": "0.19.2",
    "language-less": "0.34.2",
    "language-make": "0.22.3",
@@ -158,17 +158,17 @@
    "language-perl": "0.38.1",
    "language-php": "0.44.0",
    "language-property-list": "0.9.1",
-    "language-python": "0.50.1",
-    "language-ruby": "0.71.4",
+    "language-python": "0.51.0",
+    "language-ruby": "0.72.2",
    "language-ruby-on-rails": "0.25.3",
    "language-sass": "0.62.0",
-    "language-shellscript": "0.26.6",
+    "language-shellscript": "0.27.0",
    "language-source": "0.9.0",
    "language-sql": "0.25.10",
    "language-text": "0.7.4",
    "language-todo": "0.29.4",
    "language-toml": "0.18.2",
-    "language-typescript": "0.3.4",
+    "language-typescript": "0.4.0",
    "language-xml": "0.35.2",
    "language-yaml": "0.32.0"
  },
--- a/script/lib/create-windows-installer.js
+++ b/script/lib/create-windows-installer.js
@@ -16,6 +16,7 @@ module.exports = (packagedAppPath) => {
    loadingGif: path.join(CONFIG.repositoryRootPath, 'resources', 'win', 'loading.gif'),
    outputDirectory: CONFIG.buildOutputPath,
    noMsi: true,
+    noDelta: CONFIG.channel === 'nightly', // Delta packages are broken for nightly versions past nightly9 due to Squirrel/NuGet limitations
    remoteReleases: `https://atom.io/api/updates${archSuffix}?version=${CONFIG.computedAppVersion}`,
    setupExe: `AtomSetup${process.arch === 'x64' ? '-x64' : ''}.exe`,
    setupIcon: path.join(CONFIG.repositoryRootPath, 'resources', 'app-icons', CONFIG.channel, 'atom.ico')
@@ -28,7 +29,7 @@ module.exports = (packagedAppPath) => {
    }

    for (let nupkgPath of glob.sync(`${CONFIG.buildOutputPath}/atom-*.nupkg`)) {
-      if (!nupkgPath.includes(CONFIG.appMetadata.version)) {
+      if (!nupkgPath.includes(CONFIG.computedAppVersion)) {
        console.log(`Deleting downloaded nupkg for previous version at ${nupkgPath} to prevent it from being stored as an artifact`)
        fs.unlinkSync(nupkgPath)
      } else {
--- a/spec/project-spec.js
+++ b/spec/project-spec.js
@@ -969,6 +969,67 @@ describe('Project', () => {
    })
  })

+  describe('.observeRepositories()', () => {
+    it('invokes the observer with current and future repositories', () => {
+      const observed = []
+
+      const directory1 = temp.mkdirSync('git-repo1')
+      const gitDirPath1 = fs.absolute(path.join(__dirname, 'fixtures', 'git', 'master.git'))
+      fs.copySync(gitDirPath1, path.join(directory1, '.git'))
+
+      const directory2 = temp.mkdirSync('git-repo2')
+      const gitDirPath2 = fs.absolute(path.join(__dirname, 'fixtures', 'git', 'repo-with-submodules', 'git.git'))
+      fs.copySync(gitDirPath2, path.join(directory2, '.git'))
+
+      atom.project.setPaths([directory1])
+
+      const disposable = atom.project.observeRepositories((repo) => observed.push(repo))
+      expect(observed.length).toBe(1)
+      expect(observed[0].getReferenceTarget('refs/heads/master')).toBe('ef046e9eecaa5255ea5e9817132d4001724d6ae1')
+
+      atom.project.addPath(directory2)
+      expect(observed.length).toBe(2)
+      expect(observed[1].getReferenceTarget('refs/heads/master')).toBe('d2b0ad9cbc6f6c4372e8956e5cc5af771b2342e5')
+
+      disposable.dispose()
+    })
+  })
+
+  describe('.onDidAddRepository()', () => {
+    it('invokes callback when a path is added and the path is the root of a repository', () => {
+      const observed = []
+      const disposable = atom.project.onDidAddRepository((repo) => observed.push(repo))
+
+      const repositoryPath = path.join(__dirname, '..')
+      atom.project.addPath(repositoryPath)
+      expect(observed.length).toBe(1)
+      expect(observed[0].getOriginURL()).toContain('atom/atom')
+
+      disposable.dispose()
+    })
+
+    it('invokes callback when a path is added and the path is subdirectory of a repository', () => {
+      const observed = []
+      const disposable = atom.project.onDidAddRepository((repo) => observed.push(repo))
+
+      atom.project.addPath(__dirname)
+      expect(observed.length).toBe(1)
+      expect(observed[0].getOriginURL()).toContain('atom/atom')
+
+      disposable.dispose()
+    })
+
+    it('does not invoke callback when a path is added and the path is not part of a repository', () => {
+      const observed = []
+      const disposable = atom.project.onDidAddRepository((repo) => observed.push(repo))
+
+      atom.project.addPath(temp.mkdirSync('not-a-repository'))
+      expect(observed.length).toBe(0)
+
+      disposable.dispose()
+    })
+  })
+
  describe('.relativize(path)', () => {
    it('returns the path, relative to whichever root directory it is inside of', () => {
      atom.project.addPath(temp.mkdirSync('another-path'))
--- a/spec/text-editor-component-spec.js
+++ b/spec/text-editor-component-spec.js
@@ -818,6 +818,18 @@ describe('TextEditorComponent', () => {
      expect(element.className).toBe('editor a b')
    })

+    it('does not blow away class names managed by the component when packages change the element class name', async () => {
+      assertDocumentFocused()
+      const {component, element, editor} = buildComponent({mini: true})
+      element.classList.add('a', 'b')
+      element.focus()
+      await component.getNextUpdatePromise()
+      expect(element.className).toBe('editor mini a b is-focused')
+      element.className = 'a c d';
+      await component.getNextUpdatePromise()
+      expect(element.className).toBe('a c d editor is-focused mini')
+    })
+
    it('ignores resize events when the editor is hidden', async () => {
      const {component, element, editor} = buildComponent({autoHeight: false})
      element.style.height = 5 * component.getLineHeight() + 'px'
--- a/spec/tree-sitter-language-mode-spec.js
+++ b/spec/tree-sitter-language-mode-spec.js
@@ -12,6 +12,7 @@ const pythonGrammarPath = require.resolve('language-python/grammars/tree-sitter-
 const jsGrammarPath = require.resolve('language-javascript/grammars/tree-sitter-javascript.cson')
 const htmlGrammarPath = require.resolve('language-html/grammars/tree-sitter-html.cson')
 const ejsGrammarPath = require.resolve('language-html/grammars/tree-sitter-ejs.cson')
+const rubyGrammarPath = require.resolve('language-ruby/grammars/tree-sitter-ruby.cson')

 describe('TreeSitterLanguageMode', () => {
  let editor, buffer
@@ -346,6 +347,38 @@ describe('TreeSitterLanguageMode', () => {
      ])
    })

+    it('handles nodes that start before their first child and end after their last child', async () => {
+      const grammar = new TreeSitterGrammar(atom.grammars, rubyGrammarPath, {
+        parser: 'tree-sitter-ruby',
+        scopes: {
+          'bare_string': 'string',
+          'interpolation': 'embedded',
+          '"#{"': 'punctuation',
+          '"}"': 'punctuation',
+        }
+      })
+
+      // The bare string node `bc#{d}ef` has one child: the interpolation, and that child
+      // starts later and ends earlier than the bare string.
+      buffer.setText('a = %W( bc#{d}ef )')
+
+      const languageMode = new TreeSitterLanguageMode({buffer, grammar})
+      buffer.setLanguageMode(languageMode)
+      await nextHighlightingUpdate(languageMode)
+
+      expectTokensToEqual(editor, [
+        [
+          {text: 'a = %W( ', scopes: []},
+          {text: 'bc', scopes: ['string']},
+          {text: '#{', scopes: ['string', 'embedded', 'punctuation']},
+          {text: 'd', scopes: ['string', 'embedded']},
+          {text: '}', scopes: ['string', 'embedded', 'punctuation']},
+          {text: 'ef', scopes: ['string']},
+          {text: ' )', scopes: []},
+        ]
+      ])
+    })
+
    describe('when the buffer changes during a parse', () => {
      it('immediately parses again when the current parse completes', async () => {
        const grammar = new TreeSitterGrammar(atom.grammars, jsGrammarPath, {
@@ -707,7 +740,7 @@ describe('TreeSitterLanguageMode', () => {
      expect(getDisplayText(editor)).toBe(dedent `
        module.exports =
        class A {
-          getB (…) {
+          getB (c,…) {
            return this.f(g)
          }
        }
@@ -717,11 +750,60 @@ describe('TreeSitterLanguageMode', () => {
      expect(getDisplayText(editor)).toBe(dedent `
        module.exports =
        class A {
-          getB (…) {…}
+          getB (c,…) {…}
        }
      `)
    })

+    it('folds entire buffer rows when necessary to keep words on separate lines', async () => {
+      const grammar = new TreeSitterGrammar(atom.grammars, jsGrammarPath, {
+        parser: 'tree-sitter-javascript',
+        folds: [
+          {
+            start: {type: '{', index: 0},
+            end: {type: '}', index: -1}
+          },
+          {
+            start: {type: '(', index: 0},
+            end: {type: ')', index: -1}
+          }
+        ]
+      })
+
+      buffer.setText(dedent `
+        if (a) {
+          b
+        } else if (c) {
+          d
+        } else {
+          e
+        }
+      `)
+
+      const languageMode = new TreeSitterLanguageMode({buffer, grammar})
+      buffer.setLanguageMode(languageMode)
+      await nextHighlightingUpdate(languageMode)
+
+      // Avoid bringing the `else if...` up onto the same screen line as the preceding `if`.
+      editor.foldBufferRow(1)
+      editor.foldBufferRow(3)
+      expect(getDisplayText(editor)).toBe(dedent `
+        if (a) {…
+        } else if (c) {…
+        } else {
+          e
+        }
+      `)
+
+      // It's ok to bring the final `}` onto the same screen line as the preceding `else`.
+      editor.foldBufferRow(5)
+      expect(getDisplayText(editor)).toBe(dedent `
+        if (a) {…
+        } else if (c) {…
+        } else {…}
+      `)
+    })
+
    it('can fold nodes of specified types', async () => {
      const grammar = new TreeSitterGrammar(atom.grammars, jsGrammarPath, {
        parser: 'tree-sitter-javascript',
@@ -975,6 +1057,93 @@ describe('TreeSitterLanguageMode', () => {
      `)
    })

+    it('can target named vs anonymous nodes as fold boundaries', async () => {
+      const grammar = new TreeSitterGrammar(atom.grammars, rubyGrammarPath, {
+        parser: 'tree-sitter-ruby',
+        folds: [
+          {
+            type: 'elsif',
+            start: {index: 1},
+
+            // There are no double quotes around the `elsif` type. This indicates
+            // that we're targeting a *named* node in the syntax tree. The fold
+            // should end at the nested `elsif` node, not at the token that represents
+            // the literal string "elsif".
+            end: {type: ['else', 'elsif']}
+          },
+          {
+            type: 'else',
+
+            // There are double quotes around the `else` type. This indicates that
+            // we're targetting an *anonymous* node in the syntax tree. The fold
+            // should start at the token representing the literal string "else",
+            // not at an `else` node.
+            start: {type: '"else"'}
+          }
+        ]
+      })
+
+      buffer.setText(dedent `
+        if a
+          b
+        elsif c
+          d
+        elsif e
+          f
+        else
+          g
+        end
+      `)
+
+      const languageMode = new TreeSitterLanguageMode({buffer, grammar})
+      buffer.setLanguageMode(languageMode)
+      await nextHighlightingUpdate(languageMode)
+
+      expect(languageMode.tree.rootNode.toString()).toBe(
+        "(program (if (identifier) " +
+          "(identifier) " +
+          "(elsif (identifier) " +
+            "(identifier) " +
+            "(elsif (identifier) " +
+              "(identifier) " +
+              "(else " +
+                "(identifier))))))"
+      )
+
+      editor.foldBufferRow(2)
+      expect(getDisplayText(editor)).toBe(dedent `
+        if a
+          b
+        elsif c…
+        elsif e
+          f
+        else
+          g
+        end
+      `)
+
+      editor.foldBufferRow(4)
+      expect(getDisplayText(editor)).toBe(dedent `
+        if a
+          b
+        elsif c…
+        elsif e…
+        else
+          g
+        end
+      `)
+
+      editor.foldBufferRow(6)
+      expect(getDisplayText(editor)).toBe(dedent `
+        if a
+          b
+        elsif c…
+        elsif e…
+        else…
+        end
+      `)
+    })
+
    describe('when folding a node that ends with a line break', () => {
      it('ends the fold at the end of the previous line', async () => {
        const grammar = new TreeSitterGrammar(atom.grammars, pythonGrammarPath, {
@@ -1065,7 +1234,8 @@ describe('TreeSitterLanguageMode', () => {
      expect(getDisplayText(editor)).toBe(
        `a = html \`
            <div>
-              c\${def(…)}e\${f}g
+              c\${def(…
+              )}e\${f}g
            </div>
          \`
        `
--- a/src/initialize-application-window.coffee
+++ b/src/initialize-application-window.coffee
@@ -38,6 +38,7 @@ if global.isGeneratingSnapshot
  require('keybinding-resolver')
  require('language-html')
  require('language-javascript')
+  require('language-ruby')
  require('line-ending-selector')
  require('link')
  require('markdown-preview')
--- a/src/project.js
+++ b/src/project.js
@@ -234,6 +234,38 @@ class Project extends Model {
    return this.emitter.on('did-change-files', callback)
  }

+  // Public: Invoke the given callback with all current and future
+  // repositories in the project.
+  //
+  // * `callback` {Function} to be called with current and future
+  //    repositories.
+  //   * `repository` A {GitRepository} that is present at the time of
+  //     subscription or that is added at some later time.
+  //
+  // Returns a {Disposable} on which `.dispose()` can be called to
+  // unsubscribe.
+  observeRepositories (callback) {
+    for (const repo of this.repositories) {
+      if (repo != null) {
+        callback(repo)
+      }
+    }
+
+    return this.onDidAddRepository(callback)
+  }
+
+  // Public: Invoke the given callback when a repository is added to the
+  // project.
+  //
+  // * `callback` {Function} to be called when a repository is added.
+  //   * `repository` A {GitRepository}.
+  //
+  // Returns a {Disposable} on which `.dispose()` can be called to
+  // unsubscribe.
+  onDidAddRepository (callback) {
+    return this.emitter.on('did-add-repository', callback)
+  }
+
  /*
  Section: Accessing the git repository
  */
@@ -400,6 +432,9 @@ class Project extends Model {
      if (repo) { break }
    }
    this.repositories.push(repo != null ? repo : null)
+    if (repo != null) {
+      this.emitter.emit('did-add-repository', repo)
+    }

    if (options.emitEvent !== false) {
      this.emitter.emit('did-change-paths', this.getPaths())
--- a/src/text-editor-component.js
+++ b/src/text-editor-component.js
@@ -848,10 +848,7 @@ class TextEditorComponent {
    }

    for (let i = 0; i < newClassList.length; i++) {
-      const className = newClassList[i]
-      if (!oldClassList || !oldClassList.includes(className)) {
-        this.element.classList.add(className)
-      }
+      this.element.classList.add(newClassList[i])
    }

    this.classList = newClassList
--- a/src/tree-sitter-grammar.js
+++ b/src/tree-sitter-grammar.js
@@ -13,6 +13,7 @@ class TreeSitterGrammar {
    if (params.injectionRegExp) this.injectionRegExp = new RegExp(params.injectionRegExp)

    this.folds = params.folds || []
+    this.folds.forEach(normalizeFoldSpecification)

    this.commentStrings = {
      commentStartString: params.comments && params.comments.start,
@@ -81,3 +82,36 @@ const toSyntaxClasses = scopes =>
    : scopes.match
    ? {match: new RegExp(scopes.match), scopes: toSyntaxClasses(scopes.scopes)}
    : Object.assign({}, scopes, {scopes: toSyntaxClasses(scopes.scopes)})
+
+const NODE_NAME_REGEX = /[\w_]+/
+
+function matcherForSpec (spec) {
+  if (typeof spec === 'string') {
+    if (spec[0] === '"' && spec[spec.length - 1] === '"') {
+      return {
+        type: spec.substr(1, spec.length - 2),
+        named: false
+      }
+    }
+
+    if (!NODE_NAME_REGEX.test(spec)) {
+      return {type: spec, named: false}
+    }
+
+    return {type: spec, named: true}
+  }
+  return spec
+}
+
+function normalizeFoldSpecification (spec) {
+  if (spec.type) {
+    if (Array.isArray(spec.type)) {
+      spec.matchers = spec.type.map(matcherForSpec)
+    } else {
+      spec.matchers = [matcherForSpec(spec.type)]
+    }
+  }
+
+  if (spec.start) normalizeFoldSpecification(spec.start)
+  if (spec.end) normalizeFoldSpecification(spec.end)
+}
--- a/src/tree-sitter-language-mode.js
+++ b/src/tree-sitter-language-mode.js
@@ -9,6 +9,7 @@ const TextMateLanguageMode = require('./text-mate-language-mode')
 let nextId = 0
 const MAX_RANGE = new Range(Point.ZERO, Point.INFINITY).freeze()
 const PARSER_POOL = []
+const WORD_REGEX = /\w/

 class TreeSitterLanguageMode {
  static _patchSyntaxNode () {
@@ -41,15 +42,12 @@ class TreeSitterLanguageMode {
    this.emitRangeUpdate = this.emitRangeUpdate.bind(this)

    this.subscription = this.buffer.onDidChangeText(({changes}) => {
-      for (let i = changes.length - 1; i >= 0; i--) {
+      for (let i = 0, {length} = changes; i < length; i++) {
        const {oldRange, newRange} = changes[i]
-        const startRow = oldRange.start.row
-        const oldEndRow = oldRange.end.row
-        const newEndRow = newRange.end.row
        this.isFoldableCache.splice(
-          startRow,
-          oldEndRow - startRow,
-          ...new Array(newEndRow - startRow)
+          newRange.start.row,
+          oldRange.end.row - oldRange.start.row,
+          ...new Array(newRange.end.row - newRange.start.row)
        )
      }

@@ -272,42 +270,32 @@ class TreeSitterLanguageMode {
  }

  getFoldableRangeForNode (node, grammar, existenceOnly) {
-    const {children, type: nodeType} = node
+    const {children} = node
    const childCount = children.length
-    let childTypes

    for (var i = 0, {length} = grammar.folds; i < length; i++) {
-      const foldEntry = grammar.folds[i]
+      const foldSpec = grammar.folds[i]

-      if (foldEntry.type) {
-        if (typeof foldEntry.type === 'string') {
-          if (foldEntry.type !== nodeType) continue
-        } else {
-          if (!foldEntry.type.includes(nodeType)) continue
-        }
-      }
+      if (foldSpec.matchers && !hasMatchingFoldSpec(foldSpec.matchers, node)) continue

      let foldStart
-      const startEntry = foldEntry.start
+      const startEntry = foldSpec.start
      if (startEntry) {
+        let foldStartNode
        if (startEntry.index != null) {
-          const child = children[startEntry.index]
-          if (!child || (startEntry.type && startEntry.type !== child.type)) continue
-          foldStart = child.endPosition
+          foldStartNode = children[startEntry.index]
+          if (!foldStartNode || startEntry.matchers && !hasMatchingFoldSpec(startEntry.matchers, foldStartNode)) continue
        } else {
-          if (!childTypes) childTypes = children.map(child => child.type)
-          const index = typeof startEntry.type === 'string'
-            ? childTypes.indexOf(startEntry.type)
-            : childTypes.findIndex(type => startEntry.type.includes(type))
-          if (index === -1) continue
-          foldStart = children[index].endPosition
+          foldStartNode = children.find(child => hasMatchingFoldSpec(startEntry.matchers, child))
+          if (!foldStartNode) continue
        }
+        foldStart = new Point(foldStartNode.endPosition.row, Infinity)
      } else {
        foldStart = new Point(node.startPosition.row, Infinity)
      }

      let foldEnd
-      const endEntry = foldEntry.end
+      const endEntry = foldSpec.end
      if (endEntry) {
        let foldEndNode
        if (endEntry.index != null) {
@@ -315,19 +303,17 @@ class TreeSitterLanguageMode {
          foldEndNode = children[index]
          if (!foldEndNode || (endEntry.type && endEntry.type !== foldEndNode.type)) continue
        } else {
-          if (!childTypes) childTypes = children.map(foldEndNode => foldEndNode.type)
-          const index = typeof endEntry.type === 'string'
-            ? childTypes.indexOf(endEntry.type)
-            : childTypes.findIndex(type => endEntry.type.includes(type))
-          if (index === -1) continue
-          foldEndNode = children[index]
+          foldEndNode = children.find(child => hasMatchingFoldSpec(endEntry.matchers, child))
+          if (!foldEndNode) continue
        }

-        if (foldEndNode.endIndex - foldEndNode.startIndex > 1 && foldEndNode.startPosition.row > foldStart.row) {
-          foldEnd = new Point(foldEndNode.startPosition.row - 1, Infinity)
-        } else {
-          foldEnd = foldEndNode.startPosition
-          if (!pointIsGreater(foldEnd, foldStart)) continue
+        if (foldEndNode.startPosition.row <= foldStart.row) continue
+
+        foldEnd = foldEndNode.startPosition
+        if (this.buffer.findInRangeSync(
+          WORD_REGEX, new Range(foldEnd, new Point(foldEnd.row, Infinity))
+        )) {
+          foldEnd = new Point(foldEnd.row - 1, Infinity)
        }
      } else {
        const {endPosition} = node
@@ -714,15 +700,24 @@ class HighlightIterator {
          iterator.languageLayer.tree.rootNode.endPosition
        ).toString()
      )
+      console.log('close', iterator.closeTags.map(id => this.shortClassNameForScopeId(id)))
+      console.log('open', iterator.openTags.map(id => this.shortClassNameForScopeId(id)))
    }
  }
+
+  shortClassNameForScopeId (id) {
+    return this.languageMode.classNameForScopeId(id).replace(/syntax--/g, '')
+  }
 }

 class LayerHighlightIterator {
  constructor (languageLayer, treeCursor) {
    this.languageLayer = languageLayer
-    this.treeCursor = treeCursor
+
+    // The iterator is always positioned at either the start or the end of some node
+    // in the syntax tree.
    this.atEnd = false
+    this.treeCursor = treeCursor

    // In order to determine which selectors match its current node, the iterator maintains
    // a list of the current node's ancestors. Because the selectors can use the `:nth-child`
@@ -762,23 +757,18 @@ class LayerHighlightIterator {
      this.containingNodeChildIndices.push(childIndex)
      this.containingNodeEndIndices.push(this.treeCursor.endIndex)

-      const scopeName = this.currentScopeName()
-      if (scopeName) {
-        const id = this.idForScope(scopeName)
+      const scopeId = this._currentScopeId()
+      if (scopeId) {
        if (this.treeCursor.startIndex < targetIndex) {
-          insertContainingTag(id, this.treeCursor.startIndex, containingTags, containingTagStartIndices)
+          insertContainingTag(
+            scopeId, this.treeCursor.startIndex,
+            containingTags, containingTagStartIndices
+          )
          containingTagEndIndices.push(this.treeCursor.endIndex)
        } else {
          this.atEnd = false
-          this.openTags.push(id)
-          while (this.treeCursor.gotoFirstChild()) {
-            this.containingNodeTypes.push(this.treeCursor.nodeType)
-            this.containingNodeChildIndices.push(0)
-            const scopeName = this.currentScopeName()
-            if (scopeName) {
-              this.openTags.push(this.idForScope(scopeName))
-            }
-          }
+          this.openTags.push(scopeId)
+          this._moveDown()
          break
        }
      }
@@ -801,75 +791,27 @@ class LayerHighlightIterator {
  }

  moveToSuccessor () {
-    let didMove = false
    this.closeTags.length = 0
    this.openTags.length = 0

-    if (this.done) return
-
-    while (true) {
+    while (!this.done && !this.closeTags.length && !this.openTags.length) {
      if (this.atEnd) {
-        if (this.treeCursor.gotoNextSibling()) {
-          didMove = true
+        if (this._moveRight()) {
+          const scopeId = this._currentScopeId()
+          if (scopeId) this.openTags.push(scopeId)
          this.atEnd = false
-          const depth = this.containingNodeTypes.length
-          this.containingNodeTypes[depth - 1] = this.treeCursor.nodeType
-          this.containingNodeChildIndices[depth - 1]++
-          this.containingNodeEndIndices[depth - 1] = this.treeCursor.endIndex
-
-          while (true) {
-            const {startIndex} = this.treeCursor
-            const scopeName = this.currentScopeName()
-            if (scopeName) {
-              this.openTags.push(this.idForScope(scopeName))
-            }
-
-            if (this.treeCursor.gotoFirstChild()) {
-              if ((this.closeTags.length || this.openTags.length) &&
-                  this.treeCursor.startIndex > startIndex) {
-                this.treeCursor.gotoParent()
-                break
-              }
-
-              this.containingNodeTypes.push(this.treeCursor.nodeType)
-              this.containingNodeChildIndices.push(0)
-              this.containingNodeEndIndices.push(this.treeCursor.endIndex)
-            } else {
-              break
-            }
-          }
-        } else if (this.treeCursor.gotoParent()) {
-          this.atEnd = false
-          this.containingNodeTypes.pop()
-          this.containingNodeChildIndices.pop()
-          this.containingNodeEndIndices.pop()
+          this._moveDown()
+        } else if (this._moveUp(true)) {
+          this.atEnd = true
        } else {
          this.done = true
-          break
        }
-      } else {
+      } else if (!this._moveDown()) {
+        const scopeId = this._currentScopeId()
+        if (scopeId) this.closeTags.push(scopeId)
        this.atEnd = true
-        didMove = true
-
-        const scopeName = this.currentScopeName()
-        if (scopeName) {
-          this.closeTags.push(this.idForScope(scopeName))
-        }
-
-        const endIndex = this.treeCursor.endIndex
-        let depth = this.containingNodeEndIndices.length
-        while (depth > 1 && this.containingNodeEndIndices[depth - 2] === endIndex) {
-          this.treeCursor.gotoParent()
-          this.containingNodeTypes.pop()
-          this.containingNodeChildIndices.pop()
-          this.containingNodeEndIndices.pop()
-          --depth
-          const scopeName = this.currentScopeName()
-          if (scopeName) this.closeTags.push(this.idForScope(scopeName))
-        }
+        this._moveUp(false)
      }
-
-      if (didMove && (this.closeTags.length || this.openTags.length)) break
    }
  }

@@ -901,14 +843,77 @@ class LayerHighlightIterator {
    return this.openTags.slice()
  }

-  // Private methods
+  // Private methods  
+  _moveUp (atLastChild) {
+    let result = false
+    const {endIndex} = this.treeCursor
+    let depth = this.containingNodeEndIndices.length
+    while (depth > 1) {
+      // Once the iterator has found a scope boundary, it needs to stay at the same
+      // position, so it should not move up if the parent node ends later than the
+      // current node.
+      if ((!atLastChild || this.openTags.length || this.closeTags.length) &&
+          this.containingNodeEndIndices[depth - 2] > endIndex) {
+        break
+      }

-  currentScopeName () {
-    return applyLeafRules(this.languageLayer.grammar.scopeMap.get(
+      result = true
+      this.treeCursor.gotoParent()
+      this.containingNodeTypes.pop()
+      this.containingNodeChildIndices.pop()
+      this.containingNodeEndIndices.pop()
+      --depth
+      const scopeId = this._currentScopeId()
+      if (scopeId) this.closeTags.push(scopeId)
+    }
+    return result
+  }
+
+  _moveDown () {
+    let result = false
+    const {startIndex} = this.treeCursor
+    while (this.treeCursor.gotoFirstChild()) {
+      // Once the iterator has found a scope boundary, it needs to stay at the same
+      // position, so it should not move down if the first child node starts later than the
+      // current node.
+      if ((this.closeTags.length || this.openTags.length) &&
+          this.treeCursor.startIndex > startIndex) {
+        this.treeCursor.gotoParent()
+        break
+      }
+
+      result = true
+      this.containingNodeTypes.push(this.treeCursor.nodeType)
+      this.containingNodeChildIndices.push(0)
+      this.containingNodeEndIndices.push(this.treeCursor.endIndex)
+
+      const scopeId = this._currentScopeId()
+      if (scopeId) this.openTags.push(scopeId)
+    }
+
+    return result
+  }
+
+  _moveRight () {
+    if (this.treeCursor.gotoNextSibling()) {
+      const depth = this.containingNodeTypes.length
+      this.containingNodeTypes[depth - 1] = this.treeCursor.nodeType
+      this.containingNodeChildIndices[depth - 1]++
+      this.containingNodeEndIndices[depth - 1] = this.treeCursor.endIndex
+      return true
+    }
+  }
+
+  _currentScopeId () {
+    const rules = this.languageLayer.grammar.scopeMap.get(
      this.containingNodeTypes,
      this.containingNodeChildIndices,
      this.treeCursor.nodeIsNamed
-    ), this.treeCursor)
+    )
+    const scopes = applyLeafRules(rules, this.treeCursor)
+    if (scopes) {
+      return this.languageLayer.languageMode.grammar.idForScope(scopes)
+    }
  }

  idForScope (scopeName) {
@@ -1059,14 +1064,14 @@ function compareScopeDescriptorIterators (a, b) {
  )
 }

-function pointIsGreater (left, right) {
-  return left.row > right.row || left.row === right.row && left.column > right.column
-}
-
 function last (array) {
  return array[array.length - 1]
 }

+function hasMatchingFoldSpec (specs, node) {
+  return specs.some(({type, named}) => type === node.type && named === node.isNamed)
+}
+
 // TODO: Remove this once TreeSitterLanguageMode implements its own auto-indent system.
 [
  '_suggestedIndentForLineWithScopeAtBufferRow',