angular-cn/packages/compiler-cli/ngcc
Alex Rickabaugh 08a4f10ee7 fix(ivy): move setClassMetadata calls into a pure iife (#33337)
This commit transforms the setClassMetadata calls generated by ngtsc from:

```typescript
/*@__PURE__*/ setClassMetadata(...);
```

to:

```typescript
/*@__PURE__*/ (function() {
  setClassMetadata(...);
})();
```

Without the IIFE, terser won't remove these function calls because the
function calls have arguments that themselves are function calls or other
impure expressions. In order to make the whole block be DCE-ed by terser,
we wrap it into IIFE and mark the IIFE as pure.

It should be noted that this change doesn't have any impact on CLI* with
build-optimizer, which removes the whole setClassMetadata block within
the webpack loader, so terser or webpack itself don't get to see it at
all. This is done to prevent cross-chunk retention issues caused by
webpack's internal module registry.

* actually we do expect a short-term size regression while
https://github.com/angular/angular-cli/pull/16228
is merged and released in the next rc of the CLI. But long term this
change does nothing to CLI + build-optimizer configuration and is done
primarly to correct the seemingly correct but non-function PURE annotation
that builds not using build-optimizer could rely on.

PR Close #33337
2019-11-20 12:55:58 -08:00
..
src fix(ngcc): properly detect origin of constructor param types (#33901) 2019-11-19 11:38:33 -08:00
test fix(ivy): move setClassMetadata calls into a pure iife (#33337) 2019-11-20 12:55:58 -08:00
BUILD.bazel feat(ngcc): support version ranges in project/default configurations (#33008) 2019-10-10 13:59:57 -07:00
README.md refactor(ivy): move ngcc into a higher level folder (#29092) 2019-03-20 14:45:54 -04:00
index.ts refactor(ngcc): add support for asynchronous execution (#32427) 2019-09-09 15:55:13 -04:00
main-ivy-ngcc.ts fix(ngcc): rename the executable from `ivy-ngcc` to `ngcc` (#33140) 2019-10-14 16:29:14 +00:00
main-ngcc.ts feat(ngcc): support --async flag (defaults to true) (#33192) 2019-10-17 19:43:39 -04:00

README.md

Angular Compatibility Compiler (ngcc)

This compiler will convert node_modules compiled with ngc, into node_modules which appear to have been compiled with ngtsc.

This conversion will allow such "legacy" packages to be used by the Ivy rendering engine.

Building

The project is built using Bazel:

yarn bazel build //packages/compiler-cli/ngcc

Unit Testing

The unit tests are built and run using Bazel:

yarn bazel test //packages/compiler-cli/ngcc/test

Integration Testing

There are tests that check the behavior of the overall executable:

yarn bazel test //packages/compiler-cli/ngcc/test:integration