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
`$implicit` is being used with a template context typed as `any`).
While this diagnostic message is valuable, typing template contexts
loosely as `any` or `object` is very widespread in community packages,
and often still compiles correctly, so reporting the diagnostic as an
error may be misleading to users.
This commit changes the diagnostic to be a warning, and adds additional
information about how the user can eliminate the warning entirely -- by
refining the template context type.
Closes https://github.com/angular/vscode-ng-language-service/issues/572
PR Close#35036
This commit adds support for completions of properties on `$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
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
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
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 is a potential fix for https://github.com/angular/vscode-ng-language-service/issues/235
suggested by @andrius-pra in
47696136e3.
Currently, CRLF line endings are converted to LFs and this causes the
diagnostics span to be off in templates that use CRLF. The line endings
must be preserved in order to maintain correct span offset. The solution
is to add an option to the Tokenizer to indicate such preservation.
PR Close#33241
This commit speeds up the tests by calling `MockHost.reset()` in
`beforeEach()` instead of destroying the entire language service and
creating a new one. The creation of a new language service instance is
expensive due to the need to initialize many core Symbols when creating
a new program.
This speeds ups the test (on my local machine) from 35 secs to 15 secs.
PR Close#33200
This is the last part in refactoring of the test project.
This PR turns on strict mode for typechecking and fixed tests that
fail under this mode.
PR Close#32783
readFileContent() has the exact same functionality as readFile(), but it
is not actually part of ts.LanguageServiceHost interface.
It's not actually needed, so replace it with readFile() instead.
PR Close#32782
Remove MockData from the constructor parameters of MockTypescriptHost
since the entire Tour of Heroes (TOH) project is now loaded from disk.
Added a new method `reset()` to MockTypescriptHost that is necessary to
reset the state of the project before each spec if run to make sure
previous overrides are cleared.
PR Close#32752
`templateUrls` that do not point to actual files are now diagnosed as such
by the Language Service. Support for `styleUrls` will come in a next PR.
This introduces a utility method `getPropertyValueOfType` that scans
TypeScript ASTs until a property assignment whose initializer of a
certain type is found. This PR also notices a couple of things that
could be improved in the language-service implementation, such as
enumerating directive properties and unifying common logic, that will be
fixed in future PRs.
Part of #32564.
PR Close#32586
This commit adds a no-op test for exposing the bug in the way language
service handles CRLF line endings in templates.
There is no easy fix for now, but the test should be enabled once a fix
is in place.
PR Close#32245
This commit fixes many diagnostic tests have have incorrect/uncaught assertions.
Also added more assertions to make sure TS diagnostics are clear.
A few test util methods are removed to reduce clutter and improve readability.
PR Close#32161
Cleanup the logic in TypeScriptHost as to when langauge service state
should be synchronized with the editor state.
The model employed follows that of tsserver, in which case it is the
caller's responsiblity to synchronize host data before any LS methods
are called.
PR Close#32017
Part 2/3 of language service refactoring:
Now that the language service is a proper tsserver plugin, all LS
interfaces should return TS values. This PR refactors the
ng.getDiagnostics() API to return ts.Diagnostic[] instead of
ng.Diagnostic[].
PR Close#32115
```
NgLSHost: AngularLanguageServiceHost
NgLS: AngularLanguageService
```
NgLSHost should not depend on NgLS, because it introduces circular
dependency.
Instead, the `getTemplateAst` and `getTemplatAstAtPosition` methods should
be moved to NgLSHost and exposed as public methods.
This removes the circular dependency, and also removes the need for the
awkward 'setSite' method in NgLSHost.
PR Close#31122
Typescript 3.2 introduced BigInt type, and consequently the
implementation for checkExpressionWorker() in checkers.ts is refactored.
For NumberLiteral and StringLiteral types, 'text' filed must be present
in the Node type, therefore they must be LiteralLikeNode instead of
Node.
PR Close#27536
This commit fixes a bug whereby the caches are not cleared when the
program changes. This subsequently produces the incorrect error of
'Component ... is not included in a module ...'.
PR Close#19405
PR Close#21337
The errors produced when error were encountered while interpreting the
content of a directive was often incomprehencible. With this change
these kind of error messages should be easier to understand and diagnose.
PR Close#20459
Pusztai Tibor
Keen Yee Liau
Ayaz Hafiz
ayazhafiz
ivanwonder
Igor Minar
Alan
George Kalpakas
Chuck Jazdzewski
Miško Hevery