FileToModuleHost aliasing supports compilation within environments that have
two properties:
1. A `FileToModuleHost` exists which defines canonical module names for any
given TS file.
2. Dependency restrictions exist which prevent the import of arbitrary files
even if such files are within the .d.ts transitive closure of a
compilation ("strictdeps").
In such an environment, generated imports can only go through import paths
which are already present in the user program. The aliasing system supports
the generation and consumption of such imports at runtime.
`FileToModuleHost` aliasing does not emit re-exports in .d.ts files. This
means that it's safe to rely on alias re-exports in generated .js code (they
are guaranteed to exist at runtime) but not in template type-checking code
(since TS will not be able to follow such imports). Therefore, non-aliased
imports should be used in template type-checking code.
This commit adds a `NoAliasing` flag to `ImportFlags` and sets it when
generating imports in template type-checking code. The testing environment
is also patched to support resolution of FileToModuleHost canonical paths
within the template type-checking program, enabling testing of this change.
PR Close#34649
Previously, `ReferenceEmitter.emit()` took an `ImportMode` enum value, where
one value of the enum allowed forcing new imports to be generated when
emitting a reference to some value or type.
This commit refactors `ImportMode` to be an `ImportFlags` value instead.
Using a bit field of flags will allow future customization of reference
emitting.
PR Close#34649
Previously, when generating template type-checking code, casts to 'any' were
produced as `expr as any`, regardless of the expression. However, for
certain expression types, this led to precedence issues with the cast. For
example, `a !== b` is a `ts.BinaryExpression`, and wrapping it directly in
the cast yields `a !== b as any`, which is semantically equivalent to
`a !== (b as any)`. This is obviously not what is intended.
Instead, this commit adds a list of expression types for which a "bare"
wrapping is permitted. For other expressions, parentheses are added to
ensure correct precedence: `(a !== b) as any`
PR Close#34649
Currently, the template type-checker gives an error if there are multiple
bindings to the same input. This commit aligns the behavior of the template
type-checker with the View Engine runtime: only the first binding to a field
has any effect. The rest are ignored.
PR Close#34649
It's possible to declare multiple inputs for a directive/component which all
map to the same property name. This is usually done in error, as only one of
any bindings to the property will "win".
In the template type-checker, an error was previously being raised as a
result of this ambiguity. Specifically, a type constructor was produced
which required a binding for each field, but only one of the fields had
a value via the binding. TypeScript would (rightfully) error on missing
values for the remaining fields. This ultimately was happening when the
code which generated the default values for "unset" inputs belonging to
directives or pipes used the final mapping from properties to fields as
a source for field names.
Instead, this commit uses the original list of fields to generate unset
input values, which correctly provides values for fields which shared a
property name but didn't receive the final binding.
PR Close#34649
Consider a library that uses a shared constant for host bindings. e.g.
```ts
export const BASE_BINDINGS= {
'[class.mat-themed]': '_isThemed',
}
----
@Directive({
host: {...BASE_BINDINGS, '(click)': '...'}
})
export class Dir1 {}
@Directive({
host: {...BASE_BINDINGS, '(click)': '...'}
})
export class Dir2 {}
```
Previously when these components were shipped as part of the
library to NPM, consumers were able to consume `Dir1` and `Dir2`.
No errors showed up.
Now with Ivy, when ngcc tries to process the library, an error
will be thrown. The error is stating that the host bindings should
be an object (which they obviously are). This happens because
TypeScript transforms the object spread to individual
`Object.assign` calls (for compatibility).
The partial evaluator used by the `@Directive` annotation handler
is unable to process this expression because there is no
integrated support for `Object.assign`. In View Engine, this was
not a problem because the `metadata.json` files from the library
were used to compute the host bindings.
Fixes#34659
PR Close#34661
This commit adds an `exclusive` parameter to the
`FileSystem.writeFile()` method. When this parameter is
true, the method will fail with an `EEXIST` error if the
file already exists on disk.
PR Close#34722
The major one that affects the angular repo is the removal of the bootstrap attribute in nodejs_binary, nodejs_test and jasmine_node_test in favor of using templated_args --node_options=--require=/path/to/script. The side-effect of this is that the bootstrap script does not get the require.resolve patches with explicitly loading the targets _loader.js file.
PR Close#34736
Currently ngtsc looks for the first `ConstructorDeclaration` when figuring out what the parameters are so that it can generate the DI instructions. The problem is that if a constructor has overloads, it'll have several `ConstructorDeclaration` members with a different number of parameters. These changes tweak the logic so it looks for the constructor implementation.
PR Close#34590
Currently the decorator handlers are run against all `SourceFile`s in the compilation, but we shouldn't be doing it against declaration files. This initially came up as a CI issue in #33264 where it was worked around only for the `DirectiveDecoratorHandler`. These changes move the logic into the `TraitCompiler` and `DecorationAnalyzer` so that it applies to all of the handlers.
PR Close#34557
The major one that affects the angular repo is the removal of the bootstrap attribute in nodejs_binary, nodejs_test and jasmine_node_test in favor of using templated_args --node_options=--require=/path/to/script. The side-effect of this is that the bootstrap script does not get the require.resolve patches with explicitly loading the targets _loader.js file.
PR Close#34589
In some cases TypeScript is unable to identify a valid
symbol for an export. In this case it returns an "unknown"
symbol, which does not reference any declarations.
This fix ensures that ngcc does not crash if such a symbol
is encountered by checking whether `symbol.declarations`
exists before accessing it.
The commit does not contain a unit test as it was not possible
to recreate a scenario that had such an "unknown" symbol in
the unit test environment. The fix has been manually checked
against that original issue; and also this check is equivalent to
similar checks elsewhere in the code, e.g.
https://github.com/angular/angular/blob/8d0de89e/packages/compiler-cli/src/ngtsc/reflection/src/typescript.ts#L309Fixes#34560
PR Close#34658
Previously, it was required that both `fullTemplateTypeCheck` and
`strictTemplates` had to be enabled for strict mode to be enabled. This
is strange, as `strictTemplates` implies `fullTemplateTypeCheck`. This
commit makes setting the `fullTemplateTypeCheck` flag optional so that
strict mode can be enabled by just setting `strictTemplates`.
PR Close#34195
It is now an error if '"fullTemplateTypeCheck"' is disabled while
`"strictTemplates"` is enabled, as enabling the latter implies that the
former is also enabled.
PR Close#34195
The compiler has a translation mechanism to convert from an Angular
`Type` to a `ts.TypeNode`, as appropriate. Prior to this change, it
would translate certain Angular expressions into their value equivalent
in TypeScript, instead of the correct type equivalent. This was possible
as the `ExpressionVisitor` interface is not strictly typed, with `any`s
being used for return values.
For example, a literal object was translated into a
`ts.ObjectLiteralExpression`, containing `ts.PropertyAssignment` nodes
as its entries. This has worked without issues as their printed
representation is identical, however it was incorrect from a semantic
point of view. Instead, a `ts.TypeLiteralNode` is created with
`ts.PropertySignature` as its members, which corresponds with the type
declaration of an object literal.
PR Close#34021
In Ivy's template type checker, type constructors are created for all
directive types to allow for accurate type inference to work. The type
checker has two strategies for dealing with such type constructors:
1. They can be emitted local to the type check block/type check file.
2. They can be emitted as static `ngTypeCtor` field into the directive
itself.
The first strategy is preferred, as it avoids having to update the
directive type which would cause a more expensive rebuild. However, this
strategy is not suitable for directives that have constrained generic
types, as those constraints would need to be present on the local type
constructor declaration. This is not trivial, as it requires that any
type references within a type parameter's constraint are imported into
the local context of the type check block.
For example, lets consider the `NgForOf` directive from '@angular/core'
looks as follows:
```typescript
import {NgIterable} from '@angular/core';
export class NgForOf<T, U extends NgIterable<T>> {}
```
The type constructor will then have the signature:
`(o: Pick<i1.NgForOf<T, U>, 'ngForOf'>) => i1.NgForOf<T, U>`
Notice how this refers to the type parameters `T` and `U`, so the type
constructor needs to be emitted into a scope where those types are
available, _and_ have the correct constraints.
Previously, the template type checker would detect the situation where a
type parameter is constrained, and would emit the type constructor
using strategy 2; within the directive type itself. This approach makes
any type references within the generic type constraints lexically
available:
```typescript
export class NgForOf<T, U extends NgIterable<T>> {
static ngTypeCtor<T = any, U extends NgIterable<T> = any>
(o: Pick<NgForOf<T, U>, 'ngForOf'>): NgForOf<T, U> { return null!; }
}
```
This commit introduces the ability to emit a type parameter with
constraints into a different context, under the condition that it can
be imported from an absolute module. This allows a generic type
constructor to be emitted into a type check block or type check file
according to strategy 1, as imports have been generated for all type
references within generic type constraints. For example:
```typescript
import * as i0 from '@angular/core';
import * as i1 from '@angular/common';
const _ctor1: <T = any, U extends i0.NgIterable<T> = any>
(o: Pick<i1.NgForOf<T, U>, 'ngForOf'>) => i1.NgForOf<T, U> = null!;
```
Notice how the generic type constraint of `U` has resulted in an import
of `@angular/core`, and the `NgIterable` is transformed into a qualified
name during the emitting process.
Resolves FW-1739
PR Close#34021
Angular View Engine uses global knowledge to compile the following code:
```typescript
export class Base {
constructor(private vcr: ViewContainerRef) {}
}
@Directive({...})
export class Dir extends Base {
// constructor inherited from base
}
```
Here, `Dir` extends `Base` and inherits its constructor. To create a `Dir`
the arguments to this inherited constructor must be obtained via dependency
injection. View Engine is able to generate a correct factory for `Dir` to do
this because via metadata it knows the arguments of `Base`'s constructor,
even if `Base` is declared in a different library.
In Ivy, DI is entirely a runtime concept. Currently `Dir` is compiled with
an ngDirectiveDef field that delegates its factory to `getInheritedFactory`.
This looks for some kind of factory function on `Base`, which comes up
empty. This case looks identical to an inheritance chain with no
constructors, which works today in Ivy.
Both of these cases will now become an error in this commit. If a decorated
class inherits from an undecorated base class, a diagnostic is produced
informing the user of the need to either explicitly declare a constructor or
to decorate the base class.
PR Close#34460
Adds a compilation error if the consumer tries to pass in an undecorated class into the `providers` of an `NgModule`, or the `providers`/`viewProviders` arrays of a `Directive`/`Component`.
PR Close#34460
The function `makeTemplateDiagnostic` was accepting an error code of type
`number`, making it easy to accidentally pass an `ErrorCode` directly and
not convert it to an Angular diagnostic code first.
This commit refactors `makeTemplateDiagnostic` to accept `ErrorCode` up
front, and convert it internally. This is less error-prone.
PR Close#34460
Previously, ngtsc would perform scope analysis (which directives/pipes are
available inside a component's template) and template type-checking of that
template as separate steps. If a component's scope was somehow invalid (e.g.
its NgModule imported something which wasn't another NgModule), the
component was treated as not having a scope. This meant that during template
type-checking, errors would be produced for any invalid expressions/usage of
other components that should have been in the scope.
This commit changes ngtsc to skip template type-checking of a component if
its scope is erroneous (as opposed to not present in the first place). Thus,
users aren't overwhelmed with diagnostic errors for the template and are
only informed of the root cause of the problem: an invalid NgModule scope.
Fixes#33849
PR Close#34460
Previously each NgModule trait checked its own scope for valid declarations
during 'resolve'. This worked, but caused the LocalModuleScopeRegistry to
declare that NgModule scopes were valid even if they contained invalid
declarations.
This commit moves the generation of diagnostic errors to the
LocalModuleScopeRegistry where it belongs. Now the registry can consider an
NgModule's scope to be invalid if it contains invalid declarations.
PR Close#34460
The template type checker generates TypeScript expressions for any
expression that occurs in a template, so that TypeScript can check it
and produce errors. Some expressions as they occur in a template may be
translated into TypeScript code multiple times, for instance a binding
to a directive input that has a template guard.
One example would be the `NgIf` directive, which has a template guard to
narrow the type in the template as appropriate. Given the following
template:
```typescript
@Component({
template: '<div *ngIf="person">{{ person.name }}</div>'
})
class AppComponent {
person?: { name: string };
}
```
A type check block (TCB) with roughly the following structure is
created:
```typescript
function tcb(ctx: AppComponent) {
const t1 = NgIf.ngTypeCtor({ ngIf: ctx.person });
if (ctx.person) {
"" + ctx.person.name;
}
}
```
Notice how the `*ngIf="person"` binding is present twice: once in the
type constructor call and once in the `if` guard. As such, TypeScript
will check both instances and would produce duplicate errors, if any
were found.
Another instance is when the safe navigation operator is used, where an
expression such as `person?.name` is emitted into the TCB as
`person != null ? person!.name : undefined`. As can be seen, the
left-hand side expression `person` occurs twice in the TCB.
This commit adds the ability to insert markers into the TCB that
indicate that any errors within the expression should be ignored. This
is similar to `@ts-ignore`, however it can be applied more granularly.
PR Close#34417
Previously, the type checker would compute an absolute source span by
combining an expression AST node's `ParseSpan` (relative to the start of
the expression) together with the absolute offset of the expression as
represented in a `ParseSourceSpan`, to arrive at a span relative to the
start of the file. This information is now directly available on an
expression AST node in the `AST.sourceSpan` property, which can be used
instead.
PR Close#34417
Previously the identifiers used in the typings files were the same as
those used in the source files.
When the typings files and the source files do not match exactly, e.g.
when one of them is flattened, while the other is a deep tree, it is
possible for identifiers to be renamed.
This commit ensures that the correct identifier is used in typings files
when the typings file does not export the same name as the source file.
Fixes https://github.com/angular/ngcc-validation/pull/608
PR Close#34254
This is not expected to have any noticeable perf impact, but it wasteful
nonetheless (and annoying when stepping through the code while debugging
`ngtsc`/`ngcc`).
PR Close#34441
This commit adds three previously missing validations to
NgModule.declarations:
1. It checks that declared classes are actually within the current
compilation.
2. It checks that declared classes are directives, components, or pipes.
3. It checks that classes are declared in at most one NgModule.
PR Close#34404
A quirk of the Angular template parser is that when parsing templates in the
"default" mode, with options specified by the user, the source mapping
information in the template AST may be inaccurate. As a result, the compiler
parses the template twice: once for "emit" and once to produce an AST with
accurate sourcemaps for diagnostic production.
Previously, only the first parse was performed during analysis. The second
parse occurred during the template type-checking phase, just in time to
produce the template type-checking file.
However, with the reuse of analysis results during incremental builds, it
makes more sense to do the diagnostic parse eagerly during analysis so that
the work isn't unnecessarily repeated in subsequent builds. This commit
refactors the `ComponentDecoratorHandler` to do both parses eagerly, which
actually cleans up some complexity around template parsing as well.
PR Close#34334
During TypeScript module resolution, a lot of filesystem requests are
done. This is quite an expensive operation, so a module resolution cache
can be used to speed up the process significantly.
This commit lets the Ivy compiler perform all module resolution with a
module resolution cache. Note that the module resolution behavior can be
changed with a custom compiler host, in which case that custom host
implementation is responsible for caching. In the case of the Angular
CLI a custom compiler host with proper module resolution caching is
already in place, so the CLI already has this optimization.
PR Close#34332
The export scope of NgModules from external compilations units, as
present in .d.ts declarations, does not change during a compilation so
can be easily shared. There was already a cache but the computed export
scope was not actually stored there. This commit fixes that.
PR Close#34332
In Ivy it's illegal for a template to write to a template variable. So the
template:
```html
<ng-template let-somevar>
<button (click)="somevar = 3">Set var to 3</button>
</ng-template>
```
is erroneous and previously would fail to compile with an assertion error
from the `TemplateDefinitionBuilder`. This error wasn't particularly user-
friendly, though, as it lacked the context of which template or where the
error occurred.
In this commit, a new check in template type-checking is added which detects
such erroneous writes and produces a true diagnostic with the appropriate
context information.
Closes#33674
PR Close#34339
Previously, the compiler performed an incremental build by analyzing and
resolving all classes in the program (even unchanged ones) and then using
the dependency graph information to determine which .js files were stale and
needed to be re-emitted. This algorithm produced "correct" rebuilds, but the
cost of re-analyzing the entire program turned out to be higher than
anticipated, especially for component-heavy compilations.
To achieve performant rebuilds, it is necessary to reuse previous analysis
results if possible. Doing this safely requires knowing when prior work is
viable and when it is stale and needs to be re-done.
The new algorithm implemented by this commit is such:
1) Each incremental build starts with knowledge of the last known good
dependency graph and analysis results from the last successful build,
plus of course information about the set of files changed.
2) The previous dependency graph's information is used to determine the
set of source files which have "logically" changed. A source file is
considered logically changed if it or any of its dependencies have
physically changed (on disk) since the last successful compilation. Any
logically unchanged dependencies have their dependency information copied
over to the new dependency graph.
3) During the `TraitCompiler`'s loop to consider all source files in the
program, if a source file is logically unchanged then its previous
analyses are "adopted" (and their 'register' steps are run). If the file
is logically changed, then it is re-analyzed as usual.
4) Then, incremental build proceeds as before, with the new dependency graph
being used to determine the set of files which require re-emitting.
This analysis reuse avoids template parsing operations in many circumstances
and significantly reduces the time it takes ngtsc to rebuild a large
application.
Future work will increase performance even more, by tackling a variety of
other opportunities to reuse or avoid work.
PR Close#34288
Previously 'analyze' in the various `DecoratorHandler`s not only extracts
information from the decorators on the classes being analyzed, but also has
several side effects within the compiler:
* it can register metadata about the types involved in global metadata
trackers.
* it can register information about which .ngfactory symbols are actually
needed.
In this commit, these side-effects are moved into a new 'register' phase,
which runs after the 'analyze' step. Currently this is a no-op refactoring
as 'register' is always called directly after 'analyze'. In the future this
opens the door for re-use of prior analysis work (with only 'register' being
called, to apply the above side effects).
Also as part of this refactoring, the reification of NgModule scope
information into the incremental dependency graph is moved to the
`NgtscProgram` instead of the `TraitCompiler` (which now only manages trait
compilation and does not have other side effects).
PR Close#34288
Prior to this commit, the `IvyCompilation` tracked the state of each matched
`DecoratorHandler` on each class in the `ts.Program`, and how they
progressed through the compilation process. This tracking was originally
simple, but had grown more complicated as the compiler evolved. The state of
each specific "target" of compilation was determined by the nullability of
a number of fields on the object which tracked it.
This commit formalizes the process of compilation of each matched handler
into a new "trait" concept. A trait is some aspect of a class which gets
created when a `DecoratorHandler` matches the class. It represents an Ivy
aspect that needs to go through the compilation process.
Traits begin in a "pending" state and undergo transitions as various steps
of compilation take place. The `IvyCompilation` class is renamed to the
`TraitCompiler`, which manages the state of all of the traits in the active
program.
Making the trait concept explicit will support future work to incrementalize
the expensive analysis process of compilation.
PR Close#34288
The `ModuleWithProviders` type has an optional type parameter that
should be specified to indicate what NgModule class will be provided.
This enables the Ivy compiler to statically determine the NgModule type
from the declaration files. This type parameter will become required in
the future, however to aid in the migration the compiler will detect
code patterns where using `ModuleWithProviders` as return type is
appropriate, in which case it transforms the emitted .d.ts files to
include the generic type argument.
This should reduce the number of occurrences where `ModuleWithProviders`
is referenced without its generic type argument.
Resolves FW-389
PR Close#34235
This commit refactors the way the compiler transforms .d.ts files during
ngtsc builds. Previously the `IvyCompilation` kept track of a
`DtsFileTransformer` for each input file. Now, any number of
`DtsTransform` operations that need to be applied to a .d.ts file are
collected in the `DtsTransformRegistry`. These are then ran using a
single `DtsTransformer` so that multiple transforms can be applied
efficiently.
PR Close#34235
The metadata collector for View Engine compilations emits error symbols
for static class members that have not been initialized, which prevents
a library from building successfully when `strictMetadataEmit` is
enabled, which is recommended for libraries to avoid issues in library
consumers. This is troublesome for libraries that are adopting static
members for the Ivy template type checker: these members don't need a
value assignment as only their type is of importance, however this
causes metadata errors. As such, a library used to be required to
initialize the special static members to workaround this error,
undesirably introducing a code-size overhead in terms of emitted
JavaScript code.
This commit modifies the collector logic to specifically ignore
the special static members for Ivy's template type checker, preventing
any errors from being recorded during the metadata collection.
PR Close#34296
For Ivy's template type checker it is possible to let a directive
specify static members to allow a wider type for some input:
```typescript
export class MatSelect {
@Input() disabled: boolean;
static ngAcceptInputType_disabled: boolean | string;
}
```
This allows a binding to the `MatSelect.disabled` input to be of type
boolean or string, whereas the `disabled` property itself is only of
type boolean.
Up until now, any static `ngAcceptInputType_*` property was not
inherited for subclasses of a directive class. This is cumbersome, as
the directive's inputs are inherited, so any acceptance member should as
well. To resolve this limitation, this commit extends the flattening of
directive metadata to include the acceptance members.
Fixes#33830
Resolves FW-1759
PR Close#34296
The compiler exports a `formatDiagnostics` function which consumers can use
to print both ts and ng diagnostics. However, this function was previously
using the "old" style TypeScript diagnostics, as opposed to the modern
diagnostic printer which uses terminal colors and prints additional context
information.
This commit updates `formatDiagnostics` to use the modern formatter, plus to
update Ivy's negative error codes to Angular 'NG' errors.
The Angular CLI needs a little more work to use this function for printing
TS diagnostics, but this commit alone should fix Bazel builds as ngc-wrapped
goes through `formatDiagnostics`.
PR Close#34234
Previously, ternary expressions were emitted as:
condExpr ? trueCase : falseCase
However, this causes problems when ternary operations are nested. In
particular, a template expression of the form:
a?.b ? c : d
would have compiled to:
a == null ? null : a.b ? c : d
The ternary operator is right-associative, so that expression is interpreted
as:
a == null ? null : (a.b ? c : d)
when in reality left-associativity is desired in this particular instance:
(a == null ? null : a.b) ? c : d
This commit adds a check in the expression translator to detect such
left-associative usages of ternaries and to enforce such associativity with
parentheses when necessary.
A test is also added for the template type-checking expression translator,
to ensure it correctly produces right-associative expressions for ternaries
in the user's template.
Fixes#34087
PR Close#34221
Fixes ngtsc incorrectly logging an unknown element diagnostic for HTML elements that are inside an SVG `foreignObject` with the `xhtml` namespace.
Fixes#34171.
PR Close#34178
Now that `@angular/localize` can interpret multiple legacy message ids in the
metablock of a `$localize` tagged template string, this commit adds those
ids to each i18n message extracted from component templates, but only if
the `enableI18nLegacyMessageIdFormat` is not `false`.
PR Close#34135
For injectables, we currently generate a factory function in the
injectable def (prov) that delegates to the factory function in
the factory def (fac). It looks something like this:
```
factory: function(t) { return Svc.fac(t); }
```
The extra wrapper function is unnecessary since the args for
the factory functions are the same. This commit changes the
compiler to generate this instead:
```
factory: Svc.fac
```
Because we are generating less code for each injectable, we
should see some modest code size savings. AIO's main bundle
is about 1 KB smaller.
PR Close#34076
