The ESM loader when used with patched Bazel module resolution
handled subpaths incorrectly. e.g.
`@bazel/concatjs/tsc_wrapped/internal/index.js` could be incorrectly
resolved to `@bazel/concatjs/index.js`.

This commit fixes the flawed logic. Also we prioritize the ESM attempts
before the original specifier. This is necessary because otherwise
the default Node resolution (using `require.resolve`) may incorrectly
prefer the `index.js` file over a `index.mjs` when a directory is
imported.

PR Close #48521

We use `bazel/esbuild` in various places (e.g. for app bundling tests).
These tests rely on the Angular Compiler-CLI itself for e.g. linking
or the Terser configuration. Since everything in this repo is now
strict ESM, the ESBuild configs (which are already ESM-supported)
need to import from `//packages/compiler-cli`. We also need to be
able to leverage our existing ESM Bazel loader for this though as
otherwise resolution would fail.

Long-term we can remove this if everything in the compiler-cli
would use `.mjs` extensions and the import paths would also specify
an explicit extension. See: https://nodejs.org/api/esm.html#mandatory-file-extensions

PR Close #48521

The symbol extractor test tool now runs with ESM too. This commit
makes it ESM compatible.

PR Close #48521

Switches all `core/test/bundling` tests to not rely on
CommonJS-specific features like `require.resolve

PR Close #48521

…48521)

Update dev-infra's build-tooling since multiple ESM changes have
landed there. e.g. not relying on `require.main === module` for API
bundling. This will allow us to also execute all dev-infra rules
in ESM because we plan on applying our ESM patching to `ts_library`
(which would also affect build-tooling then).

PR Close #48521

…o JS output (#48521)

If tests are bundled using e.g. esbuild, the `ee` symbols may
be rewritten to `\u0275\u0275`. This breaks assertions that
rely on `Function.toString`. We can avoid this string comparison
and make it more future proof by just comparing the symbols directly.

PR Close #48521

Since Karma with Bazel does not support ESM natively, we bundle the
tests using ESBuild into a single AMD file. This not only solves the
ESM issue until we can run browser ESM tests natively (also pending
in the components repo - the esbuild generation follows ESM semantics
but since collapsed we don't rely on the real module system).

A benefit of bundling is also faster and more reliable Karma browser
tests since only a single file needs to be loaded- compared to hundreds
of individual files.

PR Close #48521

)

The Angular CLI does not yet support schematics running as ESM. For
this reason we switch the schematics BUILD targets to explicitly
use ESM (as an exception in the repo).

PR Close #48521

Properly imports `jasmine-ajax` instead of attempting to load
some CommonJS bundle as a bootstrap dependency in Karma.

PR Close #48521

The circular deps tests should use the `.mjs` output.

PR Close #48521

)

We no longer have generated `.js` files as everything generated
is the ESM `.mjs` output. The tests need to be updated to reflect that.

PR Close #48521

The bazel tests cannot use CommonJS features like `require` and should
be updated to work with ESM. Additionally some specs are updated to
no longer assert CJS/UMD output from `ng_module`. The rule only emits
ESM now.

PR Close #48521

Switches the circular deps test to use the ESM output. The
normal `.js` devmode output is no longer available.

PR Close #48521

Since the linker is no longer being tested with CommonJS, we can remove
most of the CJS/ESM interop trickery.

PR Close #48521

Refactors ngcc to only rely on ESM features because CJS
is no longer needed & tested.

PR Close #48521

Updates compiler-cli & tests to be full ESM compatible. Tests
no longer with CommonJS.

PR Close #48521

`platform-browser` tests now run in ESM and with `.mjs` output, so
the build targets and tests need to be updated.

Here we change the `zone_event_unpatched` script to include the
`.init` suffix that will be picked up by `spec_bundle`.

Also some circular dependency tests are updated to refer to the
`.mjs` files.

PR Close #48521

* Switches to the canonical dev-infra http server
* Uses the bundle for serving.
* Switches app_bundle to simple `esbuild` since the test relies
  on `ngDevMode` which `app_bundle` elides as optimization.

PR Close #48521

Introduces a variant of `jasmine_node_test` that works with async/await
in combination with ZoneJS. This is needed for tests relying on
async/await in combinatin with change detection.

Browser tests are already benefting from ESbuild async-await
downleveling. Node tests would ideally not need this, but until
ZoneJS supports native async/await we need to also process
source files to avoid native async/await syntax.

PR Close #48521

…48521)

The ESM js files need to be referenced, and the router tests rely
on `async/await` with change detection- so a special rule is required
that downlevels `async/await` to generators (similar to the Angular CLI)

PR Close #48521

…48521)

There are two build targets which never had all its runtime dependencies
properly specified. This wasn't noticed because there were macros in
`defaults.bzl` that automatically included these deps.

In a follow-up we will clean-up this legacy auto-deps feature in
`defaults.bzl`.

PR Close #48521

Protractor does not support ESM, so we need to take all the ESM
output and bundle it into a CommonJS file. This comes at the cost
of not using actual ESM for execution, but the ESBuild bundle follows
strict ESM semantics so we can be sure it's compatible when we have
an ESM-compatible e2e test runner in the future.

PR Close #48521

The `packages/localize` package still required some trickery
to support CommonJS because tests in the repo were running as CommonJS.

This commit removes the CommonJS logic in localize and its tests, so
that only ESM is used in production & tests.

PR Close #48521

* Uses `.mjs` for circular deps tests
* Replaces `require` with ESM-equivalent. uses an import statement here
  for proper typing, and specify dependency properly.

PR Close #48521

…48521)

* Switches circular dependency tests to use the `.mjs` output.

PR Close #48521

)

* Uses the `.mjs` output of the upgrade package when checking for
  circular deps.

PR Close #48521

Tests now always run with ESM 2020, while previously they ran with
ES2015 CommonJS UMD bundles.

Since ZoneJS does not support intercepting native `async/await` syntax,
the forms test needs to use the zone-compatible variant of
`jasmine_node_tests`. This variant downlevels the native `async/await`
syntax to generators that ZoneJS can intercept. All of this is done
using the dev-infra ESBuild `spec_bundle` rule.

PR Close #48521