TypeScript 4.2 has changed its emitted syntax for synthetic constructors
when using `downlevelIteration`, which affects ES5 bundles that have
been downleveled from ES2015 bundles. This is typically the case for UMD
bundles in the APF spec, as they are generated by downleveling the
ESM2015 bundle into ES5. ngcc needs to detect the new syntax in order to
correctly identify synthesized constructor functions in ES5 bundles.
Fixes#41298
PR Close#41305
This commit complements the support for the `__spreadArray` helper that
was added in microsoft/TypeScript#41523. The prior helpers `__spread`
and `__spreadArrays` used the `__read` helper internally, but the helper
is now emitted as an argument to `__spreadArray` so ngcc now needs to
support evaluating it statically. The real implementation of `__read`
reads an iterable into an array, but for ngcc's static evaluation
support it is sufficient to only deal with arrays as is. Additionally,
the optional `n` parameter is not supported as that is only emitted for
array destructuring syntax, which ngcc does not have to support.
PR Close#41201
In TypeScript 4.2 the `__spread` and `__spreadArrays` helpers were both
replaced by the new helper function `__spreadArray` in
microsoft/TypeScript#41523. These helpers may be used in downleveled
JavaScript bundles that ngcc has to process, so ngcc has the ability to
statically detect these helpers and provide evaluation logic for them.
Because Angular is adopting support for TypeScript 4.2 it becomes
possible for libraries to be compiled by TypeScript 4.2 and thus ngcc
has to add support for the `__spreadArray` helper. The deprecated
`__spread` and `__spreadArrays` helpers are not affected by this change.
Closes#40394
PR Close#41201
In Angular programs, changing a file may require other files to be
emitted as well due to implicit NgModule dependencies. For example, if
the selector of a directive is changed then all components that have
that directive in their compilation scope need to be recompiled, as the
change of selector may affect the directive matching results.
Until now, the compiler solved this problem using a single dependency
graph. The implicit NgModule dependencies were represented in this
graph, such that a changed file would correctly also cause other files
to be re-emitted. This approach is limited in a few ways:
1. The file dependency graph is used to determine whether it is safe to
reuse the analysis data of an Angular decorated class. This analysis
data is invariant to unrelated changes to the NgModule scope, but
because the single dependency graph also tracked the implicit
NgModule dependencies the compiler had to consider analysis data as
stale far more often than necessary.
2. It is typical for a change to e.g. a directive to not affect its
public API—its selector, inputs, outputs, or exportAs clause—in which
case there is no need to re-emit all declarations in scope, as their
compilation output wouldn't have changed.
This commit implements a mechanism by which the compiler is able to
determine the impact of a change by comparing it to the prior
compilation. To achieve this, a new graph is maintained that tracks all
public API information of all Angular decorated symbols. During an
incremental compilation this information is compared to the information
that was captured in the most recently succeeded compilation. This
determines the exact impact of the changes to the public API, which
is then used to determine which files need to be re-emitted.
Note that the file dependency graph remains, as it is still used to
track the dependencies of analysis data. This graph does no longer track
the implicit NgModule dependencies, which allows for better reuse of
analysis data.
These changes also fix a bug where template type-checking would fail to
incorporate changes made to a transitive base class of a
directive/component. This used to be a problem because transitive base
classes were not recorded as a transitive dependency in the file
dependency graph, such that prior type-check blocks would erroneously
be reused.
This commit also fixes an incorrectness where a change to a declaration
in NgModule `A` would not cause the declarations in NgModules that
import from NgModule `A` to be re-emitted. This was intentionally
incorrect as otherwise the performance of incremental rebuilds would
have been far worse. This is no longer a concern, as the compiler is now
able to only re-emit when actually necessary.
Fixes#34867Fixes#40635Closes#40728
PR Close#40947
Previously, if a trait's analysis step resulted in diagnostics, the trait
would be considered "errored" and no further operations, including register,
would be performed. Effectively, this meant that the compiler would pretend
the class in question was actually undecorated.
However, this behavior is problematic for several reasons:
1. It leads to inaccurate diagnostics being reported downstream.
For example, if a component is put into the error state, for example due to
a template error, the NgModule which declares the component would produce a
diagnostic claiming that the declaration is neither a directive nor a pipe.
This happened because the compiler wouldn't register() the component trait,
so the component would not be recorded as actually being a directive.
2. It can cause incorrect behavior on incremental builds.
This bug is more complex, but the general issue is that if the compiler
fails to associate a component and its module, then incremental builds will
not correctly re-analyze the module when the component's template changes.
Failing to register the component as such is one link in the larger chain of
issues that result in these kinds of issues.
3. It lumps together diagnostics produced during analysis and resolve steps.
This is not causing issues currently as the dependency graph ensures the
right classes are re-analyzed when needed, instead of showing stale
diagnostics. However, the dependency graph was not intended to serve this
role, and could potentially be optimized in ways that would break this
functionality.
This commit removes the concept of an "errored" trait entirely from the
trait system. Instead, analyzed and resolved traits have corresponding (and
separate) diagnostics, in addition to potentially `null` analysis results.
Analysis (but not resolution) diagnostics are carried forward during
incremental build operations. Compilation (emit) is only performed when
a trait reaches the resolved state with no diagnostics.
This change is functionally different than before as the `register` step is
now performed even in the presence of analysis errors, as long as analysis
results are also produced. This fixes problem 1 above, and is part of the
larger solution to problem 2.
PR Close#39923
ngtsc has a robust suite of testing utilities, designed for in-memory
testing of a TypeScript compiler. Previously these utilities lived in the
`test` directory for the compiler-cli package.
This commit moves those utilities to an `ngtsc/testing` package, enabling
them to be depended on separately and opening the door for using them from
the upcoming language server testing infrastructure.
As part of this refactoring, the `fake_core` package (a lightweight API
replacement for @angular/core) is expanded to include functionality needed
for Language Service test use cases.
PR Close#39594
Previously, UMD/CommonJS class inline declarations of the form:
```ts
exports.Foo = (function() { function Foo(); return Foo; })();
```
were capturing the whole IIFE as the implementation, rather than
the inner class (i.e. `function Foo() {}` in this case). This caused
the interpreter to break when it was trying to access such an export,
since it would try to evaluate the IIFE rather than treating it as a class
declaration.
PR Close#39346
Previously, inline exports of the form `exports.foo = <implementation>;` were
being interpreted (by the ngtsc `PartialInterpeter`) as `Reference` objects.
This is not what is desired since it prevents the value of the export
from being unpacked, such as when analyzing `NgModule` declarations:
```
exports.directives = [Directive1, Directive2];
@NgImport({declarations: [exports.directives]})
class AppModule {}
```
In this example the interpreter would think that `exports.directives`
was a reference rather than an array that needs to be unpacked.
This bug was picked up by the ngcc-validation repository. See
https://github.com/angular/ngcc-validation/pull/1990 and
https://circleci.com/gh/angular/ngcc-validation/17130
PR Close#39267
Previously, any declarations that were defined "inline" were not
recognised by the `UmdReflectionHost`.
For example, the following syntax was completely unrecognized:
```ts
var Foo_1;
exports.Foo = Foo_1 = (function() {
function Foo() {}
return Foo;
})();
exports.Foo = Foo_1 = __decorate(SomeDecorator, Foo);
```
Such inline classes were ignored and not processed by ngcc.
This lack of processing led to failures in Ivy applications that relied
on UMD formats of libraries such as `syncfusion/ej2-angular-ui-components`.
Now all known inline UMD exports are recognized and processed accordingly.
Fixes#38947
PR Close#38959
Previously the `ConcreteDeclaration` and `InlineDeclaration` had
different properties for the underlying node type. And the `InlineDeclaration`
did not store a value that represented its declaration.
It turns out that a natural declaration node for an inline type is the
expression. For example in UMD/CommonJS this would be the `exports.<name>`
property access node.
So this expression is now used for the `node` of `InlineDeclaration` types
and the `expression` property is dropped.
To support this the codebase has been refactored to use a new `DeclarationNode`
type which is a union of `ts.Declaration|ts.Expression` instead of `ts.Declaration`
throughout.
PR Close#38959
This makes these tests more resilient to changes in the test code
structure. For example switching from
```
var SomeClass = <implementation>;
exports.SomeClass = SomeClass;
```
to
```
exports.SomeClass = <implementation>;
```
PR Close#38959
Previously `getDeclaration()` would only return the first node that matched
the name passed in and then assert the predicate on this single node.
It also only considered a subset of possible declaration types that we might
care about.
Now the function will parse the whole tree collecting an array of all the
nodes that match the name. It then filters this array based on the predicate
and only errors if the filtered array is empty.
This makes this function much more resilient to more esoteric code formats
such as UMD.
PR Close#38959
Sometimes UMD exports appear in the following form:
```
exports.MyClass = alias1 = alias2 = <<declaration>>
```
Previously the declaration of the export would have been captured
as `alias1 = alias2 = <<declaration>>`, which the `PartialInterpreter`
would have failed on, since it cannot handle assignments.
Now we skip over these aliases capturing only the `<<declaration>>`
expression.
Fixes#38947
PR Close#38959
UMD files export values by assigning them to an `exports` variable.
When evaluating expressions ngcc was failing to cope with expressions
like `exports.MyComponent`.
This commit fixes the `UmdReflectionHost.getDeclarationOfIdentifier()`
method to map the `exports` variable to the current source file.
PR Close#38959
The `SIMPLE_CLASS_FILE` contained a `ChildClass` that had an
internal aliases implementation and extended a `SuperClass` base
class. The call to `__extends` was using the wrong argument for
the child class.
PR Close#38959
In #38666 we changed how ngcc deals with type expressions, where it
would now always emit the original type expression into the generated
code as a "local" type value reference instead of synthesizing new
imports using an "imported" type value reference. This was done as a fix
to properly deal with renamed symbols, however it turns out that the
compiler has special handling for certain imported symbols, e.g.
`ChangeDetectorRef` from `@angular/core`. The "local" type value
reference prevented this special logic from being hit, resulting in
incorrect compilation of pipe factories.
This commit fixes the issue by manually inspecting the import of the
type expression, in order to return an "imported" type value reference.
By manually inspecting the import we continue to handle renamed symbols.
Fixes#38883
PR Close#38892
If a type has been renamed when it was exported, we need to
reference the external public alias name rather than the internal
original name for the type. Otherwise we will try to import the
type by its internal name, which is not publicly accessible.
Fixes#38238
PR Close#38666
Similarly to the change we landed in the `@angular/core` reflection
capabilities, we need to make sure that ngcc can detect pass-through
delegate constructors for classes using downleveled ES2015 output.
More details can be found in the preceding commit, and in the issue
outlining the problem: #38453.
Fixes#38453.
PR Close#38463
In TypeScript 3.8 support was added for type-only imports, which only brings in
the symbol as a type, not their value. The Angular compiler did not yet take
the type-only keyword into account when representing symbols in type positions
as value expressions. The class metadata that the compiler emits would include
the value expression for its parameter types, generating actual imports as
necessary. For type-only imports this should not be done, as it introduces an
actual import of the module that was originally just a type-only import.
This commit lets the compiler deal with type-only imports specially, preventing
a value expression from being created.
Fixes#37900
PR Close#37912
The `Logger` interface and its related classes are general purpose
and could be used by other tooling. Moving it into ngtsc is a more
suitable place from which to share it - similar to the FileSystem stuff.
PR Close#37114
Now in TS 3.9, classes in ES2015 can be wrapped in an IIFE.
This commit ensures that we still find the static properties that contain
decorator information, even if they are attached to the adjacent node
of the class, rather than the implementation or declaration.
Fixes#37330
PR Close#37436
In ES2015 IIFE wrapped classes, the identifier that would reference the class
of the NgModule may be an alias variable. Previously the `Esm2015ReflectionHost`
was not able to match this alias to the original class declaration. This resulted
in failing to identify some `ModuleWithProviders` functions in such case.
These IIFE wrapped classes were introduced in TypeScript 3.9, which is why
this issue is only recently appearing. Since 9.1.x does not support TS 3.9
there is no reason to backport this commit to that branch.
Fixes#37189
PR Close#37206
To better check that the code is working, this commit gives a
distinct name (`DecoratedWrappedClass_1`) to the "adjacent"
class declaration in the tests.
PR Close#37206
In TypeScript 3.9 some re-export syntaxes have changed to be getter
functions (created by calls to `Object.defineProperty()`) rather than
simple property accessors.
This commit adds support into the CommonJS and UMD reflection hosts
for this style of re-export syntax.
PR Close#36989
In the CommonJS and UMD reflection hosts, the logic for computing the
`viaModule` property of `Declaration` objects was not correct for some
cases when getting the exports of modules.
In these cases it was setting `viaModule` to the path of the local module
rather than `null`.
PR Close#36989
Using backtick multiline strings leads to confusing layout
that does not fit with the surrounding indentation. Also it
can lead to test fragility due to automated code formatting.
This commit changes just one set of subject code to use
a more resilient string concatenation approach.
PR Close#36989
In TS 3.9, ES2015 output can contain ES classes that are wrapped in an
IIFE. So now ES2015 class declarations can look like one of:
```
class OuterClass1 {}
```
```
let OuterClass = class InnerClass {};
```
```
var AliasClass;
let OuterClass = AliasClass = class InnerClass {};
```
```
let OuterClass = (() => class InnerClass {}};
```
```
var AliasClass;
let OuterClass = AliasClass = (() => class InnerClass {})();
```
```
let OuterClass = (() => {
let AdjacentClass = class InnerClass {};
// ... static properties or decorators attached to `AdjacentClass`
return AdjacentClass;
})();
```
```
var AliasClass;
let OuterClass = AliasClass = (() => {
let AdjacentClass = class InnerClass {};
// ... static properties or decorators attached to `AdjacentClass`
return AdjacentClass;
})();
```
The `Esm5ReflectionHost` already handles slightly different IIFE wrappers
around function-based classes. This can be substantially reused when
fixing `Esm2015ReflectionHost`, since there is a lot of commonality
between the two.
This commit moves code from the `Esm5ReflectionHost` into the `Esm2015ReflectionHost`
and looks to share as much as possible between the two hosts.
PR Close#36989
JoostK
Alex Rickabaugh
Pete Bacon Darwin
Paul Gschwendtner
Joey Perrott