fac20bd8d1
There are two places in the ngcc processing where it needs to load the content of a file given by a general path: * when determining the format of an entry-point. To do this ngcc uses the value of the relevant property in package.json. But in the case of `main` it must parse the contents of the entry-point file to decide whether the format is UMD or CommonJS. * when parsing the source files for dependencies to determine the order in which compilation must occur. The relative imports in each file are parsed and followed recursively, looking for external imports. Previously, we naively assumed that the path would match the file name exactly. But actually we must consider the standard module resolution conventions. E.g. the extension (.js) may be missing, or the path may refer to a directory containing an index.js file. This commit fixes both places. This commit now requires the `DependencyHost` instances to check the existence of more files than before (at worst all the different possible post-fixes). This should not create a significant performance reduction for ngcc. Since the results of the checks will be cached, and similar work is done inside the TS compiler, so what we lose in doing it here, is saved later in the processing. The main performance loss would be where there are lots of files that need to be parsed for dependencies that do not end up being processed by TS. But compared to the main ngcc processing this dependency parsing is a small proportion of the work done and so should not impact much on the overall performance of ngcc. // FW-1444 PR Close #31509 |
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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