If you call api.mainModule(path, where, { lazy: true }), that main
module will not be evaluated until other code imports it at runtime, and
won't even be bundled if no other code imports it.
Closes#6132.
This is another way to fix the bug I previously fixed by passing
options.allowSyntaxError to optimisticReadJsonOrNull.
To reproduce the bug (and/or verify that it is fixed), run the following
commands in a terminal:
rm -rf meteor/packages/npm-mongo/.npm
meteor/meteor --get-ready
Before these two commits, optimisticReadJsonOrNull would throw a
SyntaxError when reading one of the .meteor-portable files because an
asynchronous write to the same file had not yet finished.
Note that the value of the "main" property must include the ".node"
extension explicitly, because I have yet to encounter an npm package with
a native "main" module that omits the ".node" extension, and I am loathe
to start calling files.stat(id + ".node") uselessly for every single
missing module.
Fixes#7947.
Meteor 1.4.2 has been mostly focused on improving rebuild times, but what
ultimately matters is the time from changing a file to being able to make
requests against the restarted server, and any code that runs before
server startup should be considered part of that critical path.
If you have a lot of packages, and they do non-trivial work on startup,
this commit should give you much better insight into where time is spent.
Credit to @stubailo for pushing me to provide Meteor developers with
better profiling tools, and thanks to @veered for this specific idea.
Note: because tools/tool-env/profile.js is now loaded as-is by boot.js,
certain ECMAScript features are off-limits, e.g. ...rest params.
This is a bit different from the previous strategy of invalidating
optimistic functions for specific npm package names.
Now, whenever we make changes to the contents of a specific node_modules
directory, or whenever the developer independently modifies an app's
node_modules directory, all optimistic results derived from paths
contained within that node_modules directory will be marked as dirty, and
thus may need to be recomputed.
This strategy prioritizes starting fewer watchers (just one per
node_modules directory) while still allowing npm packages to be added or
removed while the app is running:
https://github.com/meteor/meteor/pull/7668#issuecomment-255120373
The drawback is that changes within subdirectories of node_modules will
not be detected until the server is fully restarted, but that seems like
an acceptable tradeoff, since npm packages change much less often than
application code.
This reverts commit b69716d778.
Now that we have a better system for invalidating optimistic results
derived from node_modules paths, these optimizations are safe (and yes
fourseven:scss rebuilds successfully).
This fixes a bug that prevents fourseven:scss from properly rebuilding,
because the new .../node_modules/node-sass/vendor/<platform>/binding.node
file is not found by Builder#copyDirectory, because the cached results of
optimisticReaddir are the same as before the rebuild.
Unfortunately, this change introduces a small performance regression
(hundreds of milliseconds at worst), because these files.* methods are
called many times.
I think we can continue using optimistic functions here if we are more
careful about invalidating their results, especially after calling
meteorNpm.rebuildIfNonPortable, but I'll save that for a future commit.
File#computeAssignedVariables is one of the most expensive methods called
during initial startup. This change significantly reduces the number of
times it needs to call through to findAssignedGlobals, which saves quite a
bit of parsing time. The exact savings are hard to quantify, of course,
because they depend entirely on how many modules you have in your app's
node_modules directory.
Scanning for global variable assignments is only really useful in Meteor
packages, where we sometimes need to intercept assignments for the
purposes of api.export, though this is increasingly unnecessary now that
you can (and should) just import values from node_modules.
In the app, the only possible value of intercepting global variable
assignments was to prevent polluting the global scope, but we don't even
create a private scope for the app when useGlobalNamespace is true, so
there really was no point to scanning app node_modules.
This is a refinement of my previous commit 56c041c858.
The Meteor babel-runtime package does not provide substitutes for
babel-runtime/core-js/* modules, so we should not be discarding them from
the client bundle.
Fixes#7930.
Similar to the treatment given to PackageAPI in my commit
af50b4cc5b.
This clear separation of concerns will be helpful for optimizing
PackageSource#initFromPackageDir.
The options.statOrNull function is not included in the JSON.stringify key,
but it affects the results because the implementation provided by the
ImportScanner relies on scanner._getFile to return fakeFileStat for
make-believe files created by the ImportScanner.
This becomes a problem if PackageSourceBatch#getResolver accidentally uses
a Resolver created initially for the ImportScanner, or vice-versa.
In particular, when a compiler plugin calls addJavaScript with a path
different from the original file path, the ImportScanner generates two
different modules, one of which imports the other. Only one of the files
exists on disk, though, so a special implementation of statOrNull is
necessary to keep the Resolver from having to share implementation details
with the ImportScanner.
When this system fails, users of compiler plugins see errors like this:
https://github.com/meteor/meteor/pull/7668#issuecomment-251976739
It's difficult to keep track of all the factors that could affect the
output of files.realpath, so it doesn't seem feasible to replace this call
with an optimistic function.
Fortunately, it's fine if the paths returned by IsopackCache#getSourceRoot
contain symlinks, and possibly even preferable, since
~/.meteor/packages/<name>/<version>
is more consistent than
~/.meteor/packages/<name>/.<version>.<junk>++<more junk>
though the latter happens to be a symlink to the latter.
