The template type-checking engine previously would assemble a type-checking
program by inserting Type Check Blocks (TCBs) into existing user files. This
approach proved expensive, as TypeScript has to re-parse and re-type-check
those files when processing the type-checking program.
Instead, a far more performant approach is to augment the program with a
single type-checking file, into which all TCBs are generated. Additionally,
type constructors are also inlined into this file.
This is not always possible - both TCBs and type constructors can sometimes
require inlining into user code, particularly if bound generic type
parameters are present, so the approach taken is actually a hybrid. These
operations are inlined if necessary, but are otherwise generated in a single
file.
It is critically important that the original program also include an empty
version of the type-checking file, otherwise the shape of the two programs
will be different and TypeScript will throw away all the old program
information. This leads to a painfully slow type checking pass, on the same
order as the original program creation. A shim to generate this file in the
original program is therefore added.
Testing strategy: this commit is largely a refactor with no externally
observable behavioral differences, and thus no tests are needed.
PR Close#29698
This commit moves the FlatIndexGenerator to its own package, in preparation
to expand its capabilities and support re-exporting of private declarations
from NgModules.
PR Close#27743
Previously, ngtsc did not respect the angularCompilerOptions settings
for generating flat module indices. This commit adds a
FlatIndexGenerator which is used to implement those options.
FW-738 #resolve
PR Close#27497
This commit adds generation of .ngsummary.js shims alongside .ngfactory.js
shims when generated files are enabled.
Generated .ngsummary shims contain a single, null export for every exported
class with decorators that exists in the original source files. Ivy code
does not depend on summaries, so these exist only as a placeholder to allow
them to be imported and their values passed to old APIs. This preserves
backwards compatibility.
Testing strategy: this commit adds a compiler test to verify the correct
shape and contents of the generated .ngsummary.js files.
PR Close#26495
This commit refactors the shim host to be agnostic to the shims being
generated, and provides an API for generating additional shims besides
the .ngfactory.js. This will be used in a following commit to generate
.ngsummary.js shims.
Testing strategy: this refactor introduces no new behavior, so it's
sufficient that the existing tests for factory shim generation continue
to pass.
PR Close#26495
This simple refactor of the build rules renames the .ngfactory.js shim
generator to 'shims' instead of 'factories', in preparation for adding
.ngsummary.js shim generation.
Testing strategy: this commit does not introduce any new behavior and
merely moves files and symbols around. It's sufficient that the existing
ngtsc tests pass.
PR Close#26495
