This fixes the bug where commands like `meteor add-platform ios` would
fail the first time with an error that cordova-lib could not be found,
even though we attempt to install the necessary packages if they have not
already been installed.
To make a very long story short, calling moduleDoesResolve before
installing dependencies like cordova-lib was causing Node.js to cache the
_absence_ of cordova-lib/package.json permanently in the new
packageJsonCache, which cannot be invalidated or cleared by user code:
f8f20892e9/lib/internal/modules/cjs/loader.js (L245-L255)
Although we could potentially propose a change to Node to allow the
packageJsonCache to be invalidated, a more immediate solution is simply to
avoid calling moduleDoesResolve when there's any chance the module will
not resolve. Because we still want to avoid repeatedly installing Cordova
dependencies every time we run a Cordova command, we instead check whether
the necessary dependencies are installed by examining the file system.
On the server, Meteor attempts to avoid bundling node_modules code by
replacing entry point modules with a stub that calls module.useNode() (see
packages/modules-runtime/server.js). This trick allows evaluating server
node_modules natively in Node.js, faithfully preserving all Node-specific
behaviors, such as module.id being an absolute file system path, the
__dirname and __filename variables, the ability to import binary .node
modules, and so on.
However, starting in Node.js 12.16.0 (Meteor 1.9.1+), modules evaluated
natively by Node are considered ECMAScript modules (ESM) if the closest
package.json file has "type": "module" (or has an .mjs file extension).
This poses a problem for the module.useNode() trick, because ESM modules
cannot be imported synchronously using require (which is currently how
module.useNode() works).
To work around this new error, this commit checks package.json for "type":
"module" in ImportScanner#shouldUseNode to determine whether it's safe to
use the module.useNode() trick.
The good news is that ESM modules don't have access to nearly as many
Node.js-specific quirks: no module, require, or exports variables; no
__dirname, no __filename; no ability to import JSON or other non-ESM file
types (at least right now). So it seems somewhat less important for ESM
code (compared to CommonJS code) to bail out into native Node.js execution
using module.useNode(). In other words, bundling server code should not
affect its execution in nearly as many cases, if that code is ESM rather
than legacy CommonJS.
If this good news turns out to be overly optimistic, we can consider using
a different kind of bailout stub that's capable of importing ESM using
dynamic import(). For now, making sure we avoid bailing out for ESM code
like @babel/runtime/helpers/esm/* is the priority.
Commit 646fa4e3eefixed#10547 by
restricting optimisticLookupPackageJson to package.json files with a
"name" property, which effectively skipped over intermediate package.json
files with additional properties.
However, in Node.js 12.16.0 (Meteor 1.9.1+), modules evaluated natively by
Node are considered ECMAScript modules if the closest package.json file
has "type": "module" (or has an .mjs file extension). This poses a problem
for the module.useNode() trick (see packages/modules-runtime/server.js),
because ESM modules cannot be imported using require.
For example, recent versions of the @babel/runtime package have a
@babel/runtime/helpers/esm/package.json file for the ESM versions of its
helpers (which specifies "type": "module"), but that package.json file
does not have a "name" property, because it is not the root package.json
file representing the entire @babel/runtime package.
I considered making the "name" restriction configurable, but that would
have fragmented the caching of optimisticLookupPackageJson. Instead, I
made it return an array of all potentially relevant package.json objects,
which can be safely cached.
This means that the caller has to iterate over the array, but there is
only one call site for this function (in tools/isobuild/package-source.js)
right now, so that wasn't too much work.
On the server, Meteor attempts to avoid bundling node_modules code by
replacing entry point modules with a stub that calls module.useNode() (see
packages/modules-runtime/server.js). This trick allows evaluating server
node_modules natively in Node.js, faithfully preserving all Node-specific
behaviors, such as module.id being an absolute file system path, the
__dirname and __filename variables, the ability to import binary .node
modules, and so on.
However, starting in Node.js 12.16.0 (Meteor 1.9.1+), modules evaluated
natively by Node are considered ECMAScript modules (ESM) if the closest
package.json file has "type": "module" (or has an .mjs file extension).
This poses a problem for the module.useNode() trick, because ESM modules
cannot be imported synchronously using require (which is currently how
module.useNode() works).
To work around this new error, this commit checks package.json for "type":
"module" in ImportScanner#shouldUseNode to determine whether it's safe to
use the module.useNode() trick.
The good news is that ESM modules don't have access to nearly as many
Node.js-specific quirks: no module, require, or exports variables; no
__dirname, no __filename; no ability to import JSON or other non-ESM file
types (at least right now). So it seems somewhat less important for ESM
code (compared to CommonJS code) to bail out into native Node.js execution
using module.useNode(). In other words, bundling server code should not
affect its execution in nearly as many cases, if that code is ESM rather
than legacy CommonJS.
If this good news turns out to be overly optimistic, we can consider using
a different kind of bailout stub that's capable of importing ESM using
dynamic import(). For now, making sure we avoid bailing out for ESM code
like @babel/runtime/helpers/esm/* is the priority.
Commit 646fa4e3eefixed#10547 by
restricting optimisticLookupPackageJson to package.json files with a
"name" property, which effectively skipped over intermediate package.json
files with additional properties.
However, in Node.js 12.16.0 (Meteor 1.9.1+), modules evaluated natively by
Node are considered ECMAScript modules if the closest package.json file
has "type": "module" (or has an .mjs file extension). This poses a problem
for the module.useNode() trick (see packages/modules-runtime/server.js),
because ESM modules cannot be imported using require.
For example, recent versions of the @babel/runtime package have a
@babel/runtime/helpers/esm/package.json file for the ESM versions of its
helpers (which specifies "type": "module"), but that package.json file
does not have a "name" property, because it is not the root package.json
file representing the entire @babel/runtime package.
I considered making the "name" restriction configurable, but that would
have fragmented the caching of optimisticLookupPackageJson. Instead, I
made it return an array of all potentially relevant package.json objects,
which can be safely cached.
This means that the caller has to iterate over the array, but there is
only one call site for this function (in tools/isobuild/package-source.js)
right now, so that wasn't too much work.
source-map 0.7.0+ has a much faster Rust WASM implementation.
Because this needs to be loaded, the constructor is now asynchronous.
The consumer should also be destroyed after it's no longer needed.
Using fs.writeFileSync in a serial style becomes especially costly when
we're writing a lot of files. In a recent profiling exercise I did on
Windows, nearly 80% of the time taken by Builder#_copyDirectory was spent
just closing the written files. By using the asynchronous fs.writeFile
function, we should be able to parallelize at least some of this work, and
await all the promises at the very end of copying the directory.
