Source-maps can be linked to from a source-file by a comment at
the end of the file.
Previously the `SourceFileLoader` would read
the first comment that matched `//# sourceMappingURL=` but
this is not valid since some bundlers may include embedded
source-files that contain such a comment.
Now we only look for this comment in the last non-empty line
in the file.
PR Close#32912
Webpack and other build tools sometimes inline the contents of the
source files in their generated source-maps, and at the same time
change the paths to be prefixed with a protocol, such as `webpack://`.
This can confuse tools that need to read these paths, so now it is
possible to provide a mapping to where these files originated.
PR Close#32912
This method will allow us to find the original location given a
generated location, which is useful in fine grained work with
source-mapping. E.g. in `$localize` tooling.
PR Close#32912
The `SourceFile` and associated code is general and reusable in
other projects (such as `@angular/localize`). Moving it to `ngtsc`
makes it more easily shared.
PR Close#37114
