Under strict mode, the language service fails to typecheck nullable
symbols that have already been verified to be non-null.
This generates incorrect (false positive) and confusing diagnostics
for users.
To work around this issue in the short term, this commit changes the
diagnostic message from an error to a suggestion, and prompts users to
use the safe navigation operator (?) or non-null assertion operator (!).
For example, instead of
```typescript
{{ optional && optional.toString() }}
```
the following is cleaner:
```typescript
{{ optional?.toString() }}
{{ optional!.toString() }}
```
Note that with this change, users who legitimately make a typo in their
code will no longer see an error. I think this is acceptable, since
false positive is worse than false negative. However, if users follow
the suggestion, add ? or ! to their code, then the error will be surfaced.
This seems a reasonable trade-off.
References:
1. Safe navigation operator (?)
https://angular.io/guide/template-syntax#the-safe-navigation-operator----and-null-property-paths
2. Non-null assertion operator (!)
https://angular.io/guide/template-syntax#the-non-null-assertion-operator---
PR closes https://github.com/angular/angular/pull/35070
PR closes https://github.com/angular/vscode-ng-language-service/issues/589
PR Close#35200
The language service reports an error when a directive's template
context is missing a member that is being used in a template (e.g. if
`$implicit` is being used with a template context typed as `any`).
While this diagnostic message is valuable, typing template contexts
loosely as `any` or `object` is very widespread in community packages,
and often still compiles correctly, so reporting the diagnostic as an
error may be misleading to users.
This commit changes the diagnostic to be a warning, and adds additional
information about how the user can eliminate the warning entirely -- by
refining the template context type.
Closes https://github.com/angular/vscode-ng-language-service/issues/572
PR Close#35036
Sometimes, a request for definitions will return multiple of the same
definition. This can happen in at least the cases of
- two-way bindings (one of the same definition for the property and
event binding)
- multiple template binding expressions in the same attribute
- something like "*ngFor="let i of items; trackBy: test" has two
template bindings, resulting in two template binding ASTs at the
same location (the attribute span). The language service then parses
both of these bindings individually, resulting in two independent
but identical definitions. For more context, see https://github.com/angular/angular/pull/34847#discussion_r371006680.
This commit prunes duplicate definitions by signing definitions with
their location, and checking if that location signature has been seen in
a previous definition returned to the client.
PR Close#34995
This commit adds support for completions of properties on `$event`
variables in bound outputs.
This is the second major PR to support completions for `$event`
variables (https://github.com/angular/vscode-ng-language-service/issues/531).
The final completion support that must be provided is for `$event`
variables in bindings targeting DOM events, like `(click)`.
PR Close#34570
For the structural directive, the 'path' will contain multiple `BoundDirectivePropertyAst` which depends on the number of directive property in the attribute value(e.g. '*ngFor="let item of []; trackBy: test;"', it has 2 `BoundDirectivePropertyAst`, 'ngForOf' and 'ngForTrackBy').
PR Close#34847
As part of the effort to tighten the API surface of
`TypeScriptServiceHost` in preparation for the migration to Ivy, I realized
some recently added APIs are not strictly needed.
They can be safely removed without sacrificing functionality.
This allows us to clean up the code, especially in the implementation of
QuickInfo, where the `TypeScriptServiceHost` is leaked outside of the
`LanguageService` class.
This refactoring also cleans up some duplicate code where the QuickInfo
object is generated. The logic is now consolidated into a simple
`createQuickInfo` method shared across two different implementations.
PR Close#34941
Right now, if an Angular diagnostic is generated for a TypeScript node,
the span points to the decorator Identifier, i.e. the Identifier node
like `@NgModule`, `@Component`, etc.
This is weird. It should point to the class name instead.
Note, we do not have a more fine-grained breakdown of the span when
diagnostics are emitted, this work remains to be done.
PR Close#34932
This commit elaborates diagnostics produced for invalid template
contexts by including the name of the embedded template type using the
template context, and in the common case that the implicity property is
being referenced (e.g. in a `for .. of ..` expression), suggesting to
refine the type of the context. This suggestion is provided because
users will sometimes use a base class as the type of the context in the
embedded view, and a more specific context later on (e.g. in an
`ngOnChanges` method).
Closes https://github.com/angular/vscode-ng-language-service/issues/251
PR Close#34751
This commit adds a regression test to check that the language service
recognizes inputs and outputs declared in a directive decorator.
See #34874.
PR Close#34875
In Angular, symbol can have multiple definitions (e.g. a two-way
binding). This commit adds support for for multiple definitions for a
queried location in a template.
PR Close#34782
This commit makes the Angular Language Service interface a strict subset
of TypeScript's Language Service by renaming all methods to be
consistent with TypeScript's.
The custom Angular `LanguageService` interface was needed before the
inception of TypeScript tsserver plugin, but is now obsolete since
Angular LS is a proper tsserver plugin.
This allows us to easily adapt to upstream TS changes in the future, and
also allows us to reuse all data types defined in TypeScript.
PR Close#34888
This commit removes some test scenarios from `parsing-cases.ts` and
colocate them with the test code instead. This makes the tests easier to
read and understand.
PR Close#34716
The compiler's `I18NHtmlParser` may expand template nodes that have
internationalization metadata attached to them; for instance,
```html
<div i18n="@@i18n-el">{{}}</div>
```
gets expanded to an AST with the i18n metadata extracted and text filled
in as necessary; to the language service, the template above, as read in
the AST, now looks something like
```html
<div>{{$implicit}}</div>
```
This is undesirable for the language service because we want to preserve
the original form of the source template source code, and have
information about the original values of the template. The language
service also does not need to use an i18n parser -- we don't generate
any template output.
To fix this turns out to be as easy as moving to using a raw
`HtmlParser`.
---
A note on the testing strategy: as mentioned above, we don't need to use
an i18n parser, but we don't **not** need to use one if the parser
does not heavily modify the template AST. For this reason, the tests
target the functionality of not modifying a template with i18n metadata
rather than testing that the language service does not use an i18n parser.
---
Closes https://github.com/angular/vscode-ng-language-service/issues/272
PR Close#34531
Currently, the language service provides completions in a template node
attribute by first checking if the attribute contains template bindings
to provide completions for, and then providing completions for the
expression in the attribute.
In the latter case, the expression AST was being constructed
"synthetically" inside the language service, in particular declaring the
expression to be a `PropertyRead` with an implicit receiver.
Unfortunately, this AST can be incorrect if the expression is actually a
property read on a component property receiver (e.g. when reading
`key` in the expression `obj.key`, `obj` is the receiver).
The fix is pretty simple - rather than a synthetic construction of the
AST, ask the expression parser to parse the expression in the attribute.
Fixes https://github.com/angular/vscode-ng-language-service/issues/523
PR Close#34517
This commit fixes a bug in which we do testing for completions.
Subsequently, this exposes another bug in our implementation whereby
suggestions are not provided in "ngFor" where there should have been.
Currently, multiple test cases are grouped together in a single
template. This requires the template to be somewhat complete so that
test cases that depend on variables declared earlier would pass.
Consider the following example:
```
template: `
<div *ngFor="let ~{for-person}person of ~{for-people}people">
<span>Name: {{~{for-interp-person}person.~{for-interp-name}name}}</span>
<span>Age: {{person.~{for-interp-age}age}}</span>
</div>`,
```
In order to test `~{for-interp-person}`, `people` has to be included after
`~{for-people}`. This means the test case for `~{for-people}` is not
reflective of the actual use case because the variable is already there!
In real case, the expression would be incomplete, and our implementation
failed to take that into account.
This commit breaks such test into individual tests, and fix the bugs in
the underlying implementation.
PR Close#34473
Given the following HTML and cursor position:
```
<div c|></div>
^ cursor is here
```
Note that the cursor is **after** the attribute `c`.
Under the current implementation, only `Element` is included in the
path. Instead, it should be `Element -> Attribute`.
This bug occurs only for cases where the cursor is right after the Node,
and it is because the `end` position of the span is excluded from the search.
Instead, the `end` position should be included.
PR Close#34440
`let` and `of` should be considered reserved keywords in template syntax
and thus should not be part of the autocomplete suggestions.
For reference, TypeScript does not provide such completions.
This commit removes these results and cleans up the code.
PR Close#34434
The language service incorrectly reports an error if it fails to find
NgModule metadata for a particular Component / Directive. In many cases,
the use case is legit, particularly in test.
This commit removes such diagnostic message and cleans up the interface
for `TypeScriptHost.getTemplateAst()`.
PR closes https://github.com/angular/vscode-ng-language-service/issues/463
PR Close#34113
Currently, variables of an unknown type in an `*ngFor` expression are
refined to have the type of the iterable binding of the `*ngFor`
expression. Unfortunately, this is a bug for variables aliasing
[values exported by
`*ngFor`](https://angular.io/api/common/NgForOf#local-variables),
including `index` and `first`, because they are also given the type of
the binding expression, but they are not of the binding type. For
example, in
```typescript
@Component({
selector: 'test',
template: `
<div *ngFor="let hero of heroes; let i = index; let isFirst = first">
{{ hero }}
</div>
`
})
export class TestComponent {
heroes: Hero[];
}
```
The local variables `i` and `isFirst` are determined to have a type of
`Hero`, when actually their types are `number` and `boolean`,
respectively.
This commit fixes this bug by checking if the value of a variable in an
`*ngFor` expression is known to be an export and assigning the variable
the type of that export value. Only if the variable does not alias an
export is it typed with the binding value of the `*ngFor` expression.
Closes https://github.com/angular/vscode-ng-language-service/issues/460
PR Close#34089
Commit 53fc2ed8bf added support for
determining index types accessed using index signatures, but did not
include support for index types accessed using dot notation:
```typescript
const obj<T>: { [key: string]: T };
obj['stringKey']. // gets `T.` completions
obj.stringKey. // did not peviously get `T.` completions
```
This adds support for determining an index type accessed via dot
notation by rigging an object's symbol table to return the string index
signature type a property access refers to, if that property does not
explicitly exist on the object. This is very similar to @ivanwonder's
work in #29811.
`SymbolWrapper` now takes an additional parameter to explicitly set the
type of the symbol wrapped. This is done because
`SymbolTableWrapper#get` only has access to the symbol of the index
type, _not_ the index signature symbol itself. An attempt to get the
type of the index type will give an error.
Closes#29811
Closes https://github.com/angular/vscode-ng-language-service/issues/126
PR Close#33884
When performing diagnostic checks or completions, we should take into
account members and properties in the base class, if any. Otherwise, the
language service will produce a false error.
PR closes https://github.com/angular/vscode-ng-language-service/issues/93
PR Close#34041
Previously, indexing a container type would not return completions for
the indexed type because for every TypeScript type, the recorded index
type was always marked as `undefined`, regardless of the index
signature.
This PR now returns the index type of TypeScript containers with numeric
or string index signatures. This allows use to generate completions for
arrays and defined index types:
```typescript
interface Container<T> {
[key: string]: T;
}
const ctr: Container<T>;
ctr['stringKey']. // gives `T.` completions
const arr: T[];
arr[0]. // gives `T.` completions
```
Note that this does _not_ provide completions for properties indexed by
string literals, e.g.
```typescript
interface Container<T> {
foo: T;
}
const ctr: Container<T>;
ctr['foo']. // does not give `T.` completions
```
Closes angular/vscode-ng-language-service#110
Closes angular/vscode-ng-language-service#277
PR Close#33775
This commit fixes a bug whereby completions for attribute values are only
provided for directives that support the micro-syntax format, all other
bindings are ignored.
I'm not sure if this is a regresssion or a bug, because there were no
tests prior to this.
PR Close#33839
This commit fixes a few issues with helper method
`getBuiltInTypeFromTsType`.
1. The function is wrongly named. It should be the other way round.
2. The ts.Type returned by the function should not contain any value.
This is because for some data types like Number and String, the
SourceFile (context.node) is not the correct value. Value is never
needed for program correctness in this case.
PR Close#33778
This commit fixes a bug brought up by @andrius-pra whereby the language
service host would recompute the analyzed modules even when none of the
source files changes. This is due to a bug in our unit test that
precludes non-TS files from incrementing the project version.
Consequently, when the external template is updated, the program remains
the same.
With the bug fixed, the next step is to figure out if any source files
have been added / changed / removed since the last computation. The
previously analyzed could be safely retained only when none of these
operations happen.
PR Close#33806
The method `getTemplateReferences()` appears in both the LanguageService
interface and LanguageServiceHost interface. It should belong in the
latter and not the former, since the former deals with the semantics of
the language and not the mechanics.
PR Close#33807
Keen Yee Liau
Ayaz Hafiz
ayazhafiz
ivanwonder
Paul Gschwendtner
Keen Yee Liau
Igor Minar