BREAKING CHANGE:
Switching default of `emitDistinctChangesOnlyDefaultValue`
which changes the default behavior and may cause some applications which
rely on the incorrect behavior to fail.
`emitDistinctChangesOnly` flag has also been deprecated and will be
removed in a future major release.
The previous implementation would fire changes `QueryList.changes.subscribe`
whenever the `QueryList` was recomputed. This resulted in an artificially
high number of change notifications, as it is possible that recomputing
`QueryList` results in the same list. When the `QueryList` gets recomputed
is an implementation detail, and it should not be the thing that determines
how often change event should fire.
Unfortunately, fixing the behavior outright caused too many existing
applications to fail. For this reason, Angular considers this fix a
breaking fix and has introduced a flag in `@ContentChildren` and
`@ViewChildren`, that controls the behavior.
```
export class QueryCompWithStrictChangeEmitParent {
@ContentChildren('foo', {
// This option is the new default with this change.
emitDistinctChangesOnly: true,
})
foos!: QueryList<any>;
}
```
For backward compatibility before v12
`emitDistinctChangesOnlyDefaultValue` was set to `false. This change
changes the default to `true`.
PR Close#41121
Previously, injector definitions contained a `factory` property that
was used to create a new instance of the associated NgModule class.
Now this factory has been moved to its own `ɵfac` static property on the
NgModule class itself. This is inline with how directives, components and
pipes are created.
There is a small size increase to bundle sizes for each NgModule class,
because the `ɵfac` takes up a bit more space:
Before:
```js
let a = (() => {
class n {}
return n.\u0275mod = c.Cb({type: n}),
n.\u0275inj = c.Bb({factory: function(t) { return new (t || n) }, imports: [[e.a.forChild(s)], e.a]}),
n
})(),
```
After:
```js
let a = (() => {
class n {}
return n.\u0275fac = function(t) { return new (t || n) },
n.\u0275mod = c.Cb({type: n}),
n.\u0275inj = c.Bb({imports: [[r.a.forChild(s)], r.a]}),
n
})(),
```
In other words `n.\u0275fac = ` is longer than `factory: ` (by 5 characters)
and only because the tooling insists on encoding `ɵ` as `\u0275`.
This can be mitigated in a future PR by only generating the `ɵfac` property
if it is actually needed.
PR Close#41022
This change marks all relevant define* callsites as pure, causing the compiler to
emmit either @__PURE__ or @pureOrBreakMyCode annotation based on whether we are
compiling code annotated for closure or terser.
This change is needed in g3 where we don't run build optimizer but we
need the code to be annotated for the closure compiler.
Additionally this change allows for simplification of CLI and build optimizer as they
will no longer need to rewrite the generated code (there are still other places where
a build optimizer rewrite will be necessary so we can't remove it, we can only simplify it).
PR Close#41096
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
For certain generated function calls, the compiler emits a 'PURE' annotation
which informs Terser (the optimizer) about the purity of a specific function
call. This commit expands that system to produce a new Closure-specific
'pureOrBreakMyCode' annotation when targeting the Closure optimizer instead
of Terser.
PR Close#41021
Our approach for handling cyclic imports results in code that is
not easy to tree-shake, so it is not suitable for publishing in a
library.
When compiling in partial compilation mode, we are targeting
such library publication, so we now create a fatal diagnostic
error instead of trying to handle the cyclic import situation.
Closes#40678
PR Close#40782
Produces a diagnostic when we cannot resolve a component's external style sheet or external template.
The previous behavior was to throw an exception, which crashed the
Language Service.
fixes angular/vscode-ng-language-service#1079
PR Close#40660
Normally the template parsing operation normalizes all template line endings
to '\n' only. This normalization operation causes source mapping errors when
the original template uses '\r\n' line endings.
The compiler already parses templates again to create a "diagnostic"
template AST with accurate source maps, to avoid other parsing issues that
affect source map accuracy. This commit configures this diagnostic parse to
also preserve line endings.
PR Close#40597
If the template parse option `leadingTriviaChars` is configured to
consider whitespace as trivia, any trailing whitespace of an element
would be considered as leading trivia of the subsequent element, such
that its `start` span would start _after_ the whitespace. This means
that the start span cannot be used to mark the end of the current
element, as its trailing whitespace would then be included in its span.
Instead, the full start of the subsequent element should be used.
To harden the tests that for the Ivy parser, the test utility `parseR3`
has been adjusted to use the same configuration for `leadingTriviaChars`
as would be the case in its production counterpart `parseTemplate`. This
uncovered another bug in offset handling of the interpolation parser,
where the absolute offset was computed from the start source span
(which excludes leading trivia) whereas the interpolation expression
would include the leading trivia. As such, the absolute offset now also
uses the full start span.
Fixes#39148
PR Close#40513
Previous implementation would fire changes `QueryList.changes.subscribe`
whenever the `QueryList` was recomputed. This resulted in artificially
high number of change notifications, as it is possible that recomputing
`QueryList` results in the same list. When the `QueryList` gets recomputed
is an implementation detail and it should not be the thing which determines
how often change event should fire.
This change introduces a new `emitDistinctChangesOnly` option for
`ContentChildren` and `ViewChildren`.
```
export class QueryCompWithStrictChangeEmitParent {
@ContentChildren('foo', {
// This option will become the default in the future
emitDistinctChangesOnly: true,
})
foos!: QueryList<any>;
}
```
PR Close#40091
The parser has a list of tag definitions that it uses when parsing the template. Each tag has a
`contentType` which tells the parser what kind of content the tag should contain. The problem is
that the browser has two separate `title` tags (`HTMLTitleElement` and `SVGTitleElement`) and each
of them has to have a different `contentType`, otherwise the parser will throw an error further down
the pipeline.
These changes update the tag definitions so that each tag name can have multiple content types
associated with it and the correct one can be returned based on the element's prefix.
Fixes#31503.
PR Close#40259
Now that `ReadonlyFileSystem` and `PathManipulation` interfaces are
available, this commit updates the compiler-cli to use these more
focussed interfaces.
PR Close#40281
Durring analysis we find template parse errors. This commit changes
where the type checking context stores the parse errors. Previously, we
stored them on the AnalysisOutput this commit changes the errors to be
stored on the TemplateData (which is a property on the shim). That way,
the template parse errors can be grouped by template.
Previously, if a template had a parse error, we poisoned the module and
would not procede to find typecheck errors. This change does not poison
modules whose template have typecheck errors, so that ngtsc can emit
typecheck errors for templates with parse errors.
Additionally, all template diagnostics are produced in the same place.
This allows requesting just the template template diagnostics or just
other types of errors.
PR Close#40026
Refactors the i18n error tests to be unit tests in ngtsc_spec.ts. There
is two reasons for doing this.
First is that the tests in compliace_old expected an expection to be be
thrown but did not fail the test if no exception was thrown. That means
that this test could miss catching a bug. It is also a big hacky to call
compile directly and expect an exception to be thrown for diagnostics.
Also, this can easily be unit tested and an end-to-end test is not
necessary since we are not making use of the goldfiles for these tests.
It is easier to maintain and less hacky to validate that we get helpful
error messages when nesting i18n sections by calling getDiagnostics
directly.
PR Close#40026
This commit temporarily excludes classes declared in .d.ts files from checks
regarding whether providers are actually injectable.
Such classes used to be ignored (on accident) because the
`TypeScriptReflectionHost.getConstructorParameters()` method did not return
constructor parameters from d.ts files, mostly as an oversight. This was
recently fixed, but caused more providers to be exposed to this check, which
created a breakage in g3.
This commit temporarily fixes the breakage by continuing to exclude such
providers from the check, until g3 can be patched.
PR Close#40118
Prior to this change, the `setClassMetadata` call would be invoked
inside of an IIFE that was marked as pure. This allows the call to be
tree-shaken away in production builds, as the `setClassMetadata` call
is only present to make the original class metadata available to the
testing infrastructure. The pure marker is problematic, though, as the
`setClassMetadata` call does in fact have the side-effect of assigning
the metadata into class properties. This has worked under the assumption
that only build optimization tools perform tree-shaking, however modern
bundlers are also able to elide calls that have been marked pure so this
assumption does no longer hold. Instead, an `ngDevMode` guard is used
which still allows the call to be elided but only by tooling that is
configured to consider `ngDevMode` as constant `false` value.
PR Close#39987
A couple reasons to justify removing the flag:
* It adds code to the compiler that is only meant to support test cases
and not any production. We should avoid code in that's only
meant to support tests.
* The flag enables writing tests that do not mimic real-world behavior
because they allow invalid applications
PR Close#40013
This test migrates source-mapping tests to the new compliance test framework.
The original tests are found in the file at:
`packages/compiler-cli/test/ngtsc/template_mapping_spec.ts`.
These new tests also check the mappings resulting from partial compilation
followed by linking, after flattening the pair of source-maps that each
process generates.
Note that there are some differences between the mappings for full compile
and linked compile modes, due to how TypeScript and Babel use source-span
information on AST nodes. To accommodate this, there are two expectation
files for most of these source files.
PR Close#39939
The newly built compliance test runner was not using the shared source
file cache that was added in b627f7f02e,
which offers a significant performance boost to the compliance test
targets.
PR Close#39956
Previously, if a component had an external template with a hard error, the
compiler would "forget" the link between that component and its NgModule.
Additionally, the NgModule would be marked as being in error, because the
template issue would prevent the compiler from registering the component
class as a component, so from the NgModule it would look like a declaration
of a non-directive/pipe class. As a combined result, the next incremental
step could fix the template error, but would not refresh diagnostics for the
NgModule, leading to an incrementality issue.
The various facets of this problem were fixed in prior commits. This commit
adds a test verifying the above case works now as expected.
PR Close#39923
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
If a template declares a reference to a missing target then referring to
that reference from elsewhere in the template would crash the template
type checker, due to a regression introduced in #38618. This commit
fixes the crash by ensuring that the invalid reference will resolve to
a variable of type any.
Fixes#39744
PR Close#39805
When the `preserveWhitespaces` is not true, the template parser will
process the parsed AST nodes to remove excess whitespace. Since the
generated `goog.getMsg()` statements rely upon the AST nodes after
this whitespace is removed, the i18n extraction must make a second pass.
Previously this resulted in innacurrate source-spans for the i18n text and
placeholder nodes that were extracted in the second pass.
This commit fixes this by reusing the source-spans from the first pass
when extracting the nodes in the second pass.
Fixes#39671
PR Close#39717
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
Currently when we encounter an implicit method call (e.g. `{{ foo(1) }}`) and we manage to resolve
its receiver to something within the template, we assume that the method is on the receiver itself
so we generate a type checking code to reflect it. This assumption is true in most cases, but it
breaks down if the call is on an implicit receiver and the receiver itself is being invoked. E.g.
```
<div *ngFor="let fn of functions">{{ fn(1) }}</div>
```
These changes resolve the issue by generating a regular function call if the method call's receiver
is pointing to `$implicit`.
Fixes#39634.
PR Close#39686
In order to more accurately map from a node in the TCB to a template position,
we need to provide more span information in the TCB. These changes are necessary
for the Language Service to map from a TCB node back to a specific
locations in the template for actions like "find references" and
"refactor/rename". After the TS "find references" returns results,
including those in the TCB, we need to map specifically to the matching
key/value spans in the template rather than the entire source span.
This also has the benefit of producing diagnostics which align more
closely with what TypeScript produces.
The following example shows TS code and the diagnostic produced by an invalid assignment to a property:
```
let a: {age: number} = {} as any;
a.age = 'laksjdf';
^^^^^ <-- Type 'string' is not assignable to type 'number'.
```
A corollary to this in a template file would be [age]="'someString'". The diagnostic we currently produce for this is:
```
Type 'number' is not assignable to type 'string'.
1 <app-hello [greeting]="1"></app-hello>
~~~~~~~~~~~~~~
```
Notice that the underlined text includes the entire span.
If we included the keySpan for the assignment to the property,
this diagnostic underline would be more similar to the one produced by TypeScript;
that is, it would only underline “greeting”.
[design/discussion doc]
(https://docs.google.com/document/d/1FtaHdVL805wKe4E6FxVTnVHl38lICoHIjS2nThtRJ6I/edit?usp=sharing)
PR Close#39665
ngtsc will avoid emitting generated imports that would create an import
cycle in the user's program. The main way such imports can arise is when
a component would ordinarily reference its dependencies in its component
definition `directiveDefs` and `pipeDefs`. This requires adding imports,
which run the risk of creating a cycle.
When ngtsc detects that adding such an import would cause this to occur, it
instead falls back on a strategy called "remote scoping", where a side-
effectful call to `setComponentScope` in the component's NgModule file is
used to patch `directiveDefs` and `pipeDefs` onto the component. Since the
NgModule file already imports all of the component's dependencies (to
declare them in the NgModule), this approach does not risk adding a cycle.
It has several large downsides, however:
1. it breaks under `sideEffects: false` logic in bundlers including the CLI
2. it breaks tree-shaking for the given component and its dependencies
See this doc for further details: https://hackmd.io/Odw80D0pR6yfsOjg_7XCJg?view
In particular, the impact on tree-shaking was exacerbated by the naive logic
ngtsc used to employ here. When this feature was implemented, at the time of
generating the side-effectful `setComponentScope` call, the compiler did not
know which of the component's declared dependencies were actually used in
its template. This meant that unlike the generation of `directiveDefs` in
the component definition itself, `setComponentScope` calls had to list the
_entire_ compilation scope of the component's NgModule, including directives
and pipes which were not actually used in the template. This made the tree-
shaking impact much worse, since if the component's NgModule made use of any
shared NgModules (e.g. `CommonModule`), every declaration therein would
become un-treeshakable.
Today, ngtsc does have the information on which directives/pipes are
actually used in the template, but this was not being used during the remote
scoping operation. This commit modifies remote scoping to take advantage of
the extra context and only list used dependencies in `setComponentScope`
calls, which should ameliorate the tree-shaking impact somewhat.
PR Close#39662
Previously directive "queries" that relied upon a namespaced type
```ts
queries: {
'mcontent': new core.ContentChild('test2'),
}
```
caused an error to be thrown. This is now supported.
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
Removes `ViewEncapsulation.Native` which has been deprecated for several major versions.
BREAKING CHANGES:
* `ViewEncapsulation.Native` has been removed. Use `ViewEncapsulation.ShadowDom` instead. Existing
usages will be updated automatically by `ng update`.
PR Close#38882
With the introduction of incremental type checking in #36211, an
intermediate `ts.Program` for type checking is only created if there are
any templates to check. This rendered some tests ineffective at avoiding
regressions, as the intermediate `ts.Program` was required for the tests
to fail if the scenario under test would not be accounted for. This
commit adds a single component to these tests, to ensure the
intermediate `ts.Program` is in fact created.
PR Close#39011
Prior to this fix, incremental rebuilds could fail to type check due to
missing ambient types from auto-discovered declaration files in @types
directories, or type roots in general. This was caused by the
intermediary `ts.Program` that is created for template type checking,
for which a `ts.CompilerHost` was used which did not implement the
optional `directoryExists` methods. As a result, auto-discovery of types
would not be working correctly, and this would retain into the
`ts.Program` that would be created for an incremental rebuild.
This commit fixes the issue by forcing the custom `ts.CompilerHost` used
for type checking to properly delegate into the original
`ts.CompilerHost`, even for optional methods. This is accomplished using
a base class `DelegatingCompilerHost` which is typed in such a way that
newly introduced `ts.CompilerHost` methods must be accounted for.
Fixes#38979
PR Close#39011
Some compiler tests take a long time to run, even using multiple
executors. A profiling session revealed that most time is spent in
parsing source files, especially the default libraries are expensive to
parse.
The default library files are constant across all tests, so this commit
introduces a shared cache of parsed source files of the default
libraries. This achieves a significant improvement for several targets
on my machine:
//packages/compiler-cli/test/compliance: from 23s to 5s.
//packages/compiler-cli/test/ngtsc: from 115s to 11s.
Note that the number of shards for the compliance tests has been halved,
as the extra shards no longer provide any speedup.
PR Close#38909
In Ivy, template type-checking has 3 modes: basic, full, and strict. The
primary difference between basic and full modes is that basic mode only
checks the top-level template, whereas full mode descends into nested
templates (embedded views like ngIfs and ngFors). Ivy applies this approach
to all of its template type-checking, including the DOM schema checks which
validate whether an element is a valid component/directive or not.
View Engine has both the basic and the full mode, with the same distinction.
However in View Engine, DOM schema checks happen for the full template even
in the basic mode.
Ivy's behavior here is technically a "fix" as it does not make sense for
some checks to apply to the full template and others only to the top-level
view. However, since g3 relies exclusively on the basic mode of checking and
developers there are used to DOM checks applying throughout their template,
this commit re-enables the nested schema checks even in basic mode only in
g3. This is done by enabling the checks only when Closure Compiler
annotations are requested.
Outside of g3, it's recommended that applications use at least the full mode
of checking (controlled by the `fullTemplateTypeCheck` flag), and ideally
the strict mode (`strictTemplates`).
PR Close#38943
The type-to-value conversion could previously crash if a symbol was
resolved that does not have any declarations, e.g. because it's imported
from a missing module. This would typically result in a semantic
TypeScript diagnostic and halt further compilation, therefore not
reaching the type-to-value conversion logic. In Bazel however, it turns
out that Angular semantic diagnostics are requested even if there are
semantic TypeScript errors in the program, so it would then reach the
type-to-value conversation and crash.
This commit fixes the unsafe access and adds a test that ignores the
TypeScript semantic error, effectively replicating the situation as
experienced under Bazel.
Fixes#38670
PR Close#38684
Previously, localized strings had very limited or incorrect source-mapping
information available.
Now the i18n AST nodes and related output AST nodes include source-span
information about message-parts and placeholders - including closing tag
placeholders.
This information is then used when generating the final localized string
ASTs to ensure that the correct source-mapping is rendered.
See #38588 (comment)
PR Close#38645
Previously, the compiler was not able to display template parsing errors as
true `ts.Diagnostic`s that point inside the template. Instead, it would
throw an actual `Error`, and "crash" with a stack trace containing the
template errors.
Not only is this a poor user experience, but it causes the Language Service
to also crash as the user is editing a template (in actuality the LS has to
work around this bug).
With this commit, such parsing errors are converted to true template
diagnostics with appropriate span information to be displayed contextually
along with all other diagnostics. This majorly improves the user experience
and unblocks the Language Service from having to deal with the compiler
"crashing" to report errors.
PR Close#38576
Previously, the `sourceSpan` and `startSourceSpan` were the same
object, which meant that you had the following situation:
```
element = <div>some content</div>
sourceSpan = <div>
startSourceSpan = <div>
endSourceSpan = </div>
```
This made `sourceSpan` redundant and meant that if you
wanted a span for the whole element including its content
and closing tag, it had to be computed.
Now `sourceSpan` is separated from `startSourceSpan`
resulting in:
```
element = <div>some content</div>
sourceSpan = <div>some content</div>
startSourceSpan = <div>
endSourceSpan = </div>
```
PR Close#38581
The HTML parser gets an element's namespace either from the tag name
(e.g. `<svg:rect>`) or from its parent element `<svg><rect></svg>`) which
breaks down when an element is inside of an SVG `foreignElement`,
because foreign elements allow nodes from a different namespace to be
inserted into an SVG.
These changes add another flag to the tag definitions which tells child
nodes whether to try to inherit their namespaces from their parents.
It also adds a definition for `foreignObject` with the new flag,
allowing elements placed inside it to infer their namespaces instead.
Fixes#37218.
PR Close#38477
We had a couple of places where we were assuming that if a particular
symbol has a value, then it will exist at runtime. This is true in most cases,
but it breaks down for `const` enums.
Fixes#38513.
PR Close#38542
The compiler does not currently report errors when there's an `@Input()`
for a `private`, `protected`, or `readonly` directive/component class member.
This change adds an option to enable reporting errors when a template
attempts to bind to one of these restricted input fields.
PR Close#38249
Prior to this change, the template type checker would always use a
type-constructor to instantiate a directive. This type-constructor call
serves two purposes:
1. Infer any generic types for the directive instance from the inputs
that are passed in.
2. Type check the inputs that are passed into the directive's inputs.
The first purpose is only relevant when the directive actually has any
generic types and using a type-constructor for these cases inhibits
a type-check performance penalty, as a type-constructor's signature is
quite complex and needs to be generated for each directive.
This commit refactors the generated type-check blocks to only generate
a type-constructor call for directives that have generic types. Type
checking of inputs is achieved by generating individual statements for
all inputs, using assignments into the directive's fields.
Even if a type-constructor is used for type-inference of generic types
will the input checking also be achieved using the individual assignment
statements. This is done to support the rework of the language service,
which will start to extract symbol information from the type-check
blocks.
As a future optimization, it may be possible to reduce the number of
inputs passed into a type-constructor to only those inputs that
contribute the the type-inference of the generics. As this is not a
necessity at the moment this is left as follow-up work.
Closes#38185
PR Close#38249
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
For attribute bindings that target a directive's input, the template
type checker is able to verify that the type of the input expression is
compatible with the directive's declaration for said input. This
checking adheres to the `strictNullChecks` flag as configured in the
TypeScript compilation, such that errors are reported for expressions
that include `undefined` or `null` in their type if the input's
declaration does not include those types.
There was a bug with this level of type-checking for directives that
also declare coercion members, where binding an expression that includes
the `undefined` type to a directive's input that does not include the
`undefined` type would not be reported as error.
This commit fixes the bug by changing the type-constructor in type-check
code to use an intersection type of regular inputs and coerced inputs,
instead of a union type. The union type would inadvertently allow
`undefined` types to be assigned into the regular inputs, as that would
still satisfy the characteristics of a union type.
As a result of this change, you may start to see build failures if
`strictTemplates` is enabled and `strictInputTypes` is not disabled.
These errors are legitimate and some action is required to achieve a
successful build:
1. Update the templates for which an error is reported and introduce the
non-null assertion operator at the end of the expression. This
removes the `undefined` type from the expression's type, making it
appear as a valid assignment.
2. Disable `strictNullInputTypes` in the compiler options. This will
implicitly add the non-null assertion operators similar to option 1,
but all templates in the compilation are affected.
3. Update the directive's input declaration to include the `undefined`
type, if the directive is not implemented in an external library.
PR Close#38273
Kristiyan Kostadinov
Misko Hevery
Pete Bacon Darwin
Igor Minar
JoostK
Alex Rickabaugh
Zach Arend
Joey Perrott
Andrew Scott
Charles Lyding
Alan Agius
Andrew Scott