Adds support for TypeScript 4.4. High-level overview of the changes made in this PR:
* Bumps the various packages to `typescript@4.4.2` and `tslib@2.3.0`.
* The `useUnknownInCatchVariables` compiler option has been disabled so that we don't have to cast error objects explicitly everywhere.
* TS now passes in a third argument to the `__spreadArray` call inside child class constructors. I had to update a couple of places in the runtime and ngcc to be able to pick up the calls correctly.
* TS now generates code like `(0, foo)(arg1, arg2)` for imported function calls. I had to update a few of our tests to account for it. See https://github.com/microsoft/TypeScript/pull/44624.
* Our `ngtsc` test setup calls the private `matchFiles` function from TS. I had to update our usage, because a new parameter was added.
* There was one place where we were setting the readonly `hasTrailingComma` property. I updated the usage to pass in the value when constructing the object instead.
* Some browser types were updated which meant that I had to resolve some trivial type errors.
* The downlevel decorators tranform was running into an issue where the Closure synthetic comments were being emitted twice. I've worked around it by recreating the class declaration node instead of cloning it.
PR Close#43281
Currently the compiler has three different classes to represent a "call to something":
1. `MethodCall` - `foo.bar()`
2. `SafeMethodCall` - `foo?.bar()`.
3. `FunctionCall` - Any calls that don't fit into the first two classes. E.g. `foo.bar()()`.
There are a few problems with this approach:
1. It is inconistent with the TypeScript AST which only has one node: `CallExpression`.
2. It means that we have to maintain more code, because the various parts of the compiler need to know about three node types.
3. It doesn't allow us to easily implement some new JS features like safe calls (e.g. `foo.bar?.())`).
These changes rework the compiler so that it produces only one node: `Call`. The new node behaves similarly to the TypeScript `CallExpression` whose `receiver` can be any expression.
There was a similar situation in the output AST where we had an `InvokeMethodExpression` and `InvokeFunctionExpression`. I've combined both of them into `InvokeFunctionExpression`.
PR Close#42882
This function is general purpose and by moving it into the
`chars.ts` file along with similar helpers, it can be reused
in the lexer, for instance.
PR Close#43129
This function is general purpose and by moving it into the
`chars.ts` file along with similar helpers, it can be reused
in the lexer, for instance.
PR Close#42062
In combination with the TS `noImplicitOverride` compatibility changes,
we also want to follow the best-practice of adding `override` to
members which are implemented as part of abstract classes. This
commit fixes all instances which will be flagged as part of the
custom `no-implicit-override-abstract` TSLint rule.
PR Close#42512
As of ES2021, JavaScript allows using underscores as separators inside numbers, in order to make them more readable (e.g. `1_000_000` vs `1000000`). TypeScript has had support for separators for a while so these changes expand the template parser to handle them as well.
PR Close#42672
Adds support for shorthand property declarations inside Angular templates. E.g. doing `{foo, bar}` instead of `{foo: foo, bar: bar}`.
Fixes#10277.
PR Close#42421
Currently we support safe property (`a?.b`) and method (`a?.b()`) accesses, but we don't handle safe keyed reads (`a?.[0]`) which is inconsistent. These changes expand the compiler in order to support safe key read expressions as well.
PR Close#41911
TypeScript supports ECMAScript private identifiers. It can happen that
developers intend to access such members from within an expression.
This currently results in an unclear error from the lexer. e.g.
```
'Parser Error: Unexpected token # at column 1 in [{{#myField}}] in C:/test.ts@5:2
```
We could improve such errors by tokenizing private identifiers similar to
how the TypeScript scanner processes them. Later we can report better
errors in the expression parser or in the typecheck block. This commit
causes all private identifier tokens to be disallowed, so it never
reaches the type checker. This is done intentionally as private
identifiers should not be considered valid Angular syntax, especially
because private fields are not guaranteed to be accessible from within
a component/directive definition (e.g. there cases where a template
function is generated outside of the class; which results in private
members not being accessible; and this results in mixed/confusing
behavior).
Fixes#36003.
PR Close#42027
`EmptyExpr` is somewhat unique, in that it's constructed in a circumstance
where the parser has been looking for a particular token or string of tokens
and has failed to find any. This means the parser state when constructing
`EmptyExpr` is fairly unique.
This gives rise to a bug where the parser constructs `EmptyExpr` with a
backwards span - a `start` value that's beyond the `end` value. This likely
happens because of the strange state the parser is in when recovering with
`EmptyExpr`.
This commit adds a backstop/workaround to avoid constructing such broken
`EmptyExpr` spans (or any other kind of span). Eventually, the parser state
should be fixed such that this does not occur, but that requires a
significant change to the parser's functionality, so a simple fix in th
interim is in order.
PR Close#41581
This commit adds a separate span to `MethodCall` and `SafeMethodCall` which
tracks the text span between the `(` and `)` tokens of the call. Tools like
the Language Service can use this span to more accurately understand a
cursor position within a method call expression.
PR Close#41581
The parser does not include parenthesis in the AST, so if a LHS
expression would be parenthesized then its start span would start
after the opening parenthesis. Previously, some parent AST nodes would
be created with the start span of its LHS as its own start, so this
resulted in the parent AST node not encompassing the opening parenthesis
in its source span. This commit fixes the issue by capturing the start
index prior to parsing a child AST tree, which is then used as the
start of the source span of the the parent AST node that is parsed.
Fixes#40721
PR Close#40740
When parsing interpolations, if we encounter an empty interpolation
(`{{}}`), the current code uses a "pretend" value of `$implicit` for the
name as if the interplotion were really `{{$implicit}}`. This is
problematic because the spans are then incorrect downstream since they
are based off of the `$implicit` text.
This commit changes the interpretation of empty interpolations so that
the text is simply an empty string.
Fixes https://github.com/angular/vscode-ng-language-service/issues/1077
Fixes https://github.com/angular/vscode-ng-language-service/issues/1078
PR Close#40583
The Language Service uses the source span of AST nodes to recognize which
node a user has selected, given their cursor position in a template. This is
used to trigger autocompletion.
The previous source span of BindingPipe nodes created a problem when:
1) the pipe binding had no identifier (incomplete or in-progress expression)
2) the user typed trailing whitespace after the pipe character ('|')
For example, the expression `{{foo | }}`. If the cursor preceded the '}' in
that expression, the Language Service was unable to detect that the user was
autocompleting the BindingPipe expression, since the span of the BindingPipe
ended after the '|'.
This commit changes the expression parser to expand the span of BindingPipe
expressions with a missing identifier, to include any trailing whitespace.
This allows the Language Service to correctly recognize this case as
targeting the BindingPipe and complete it successfully. The `nameSpan` of
the BindingPipe is also moved to be right-aligned with the end of any
whitespace present in the pipe binding expression.
This change allows for the disabled test in the Language Service for pipe
completion in this case to be re-enabled.
PR Close#40346
Currently we check whether a property binding contains an interpolation using a regex so
that we can throw an error. The problem is that the regex doesn't account for quotes
which means that something like `[prop]="'{{ foo }}'"` will be considered an error, even
though it's not actually an interpolation.
These changes build on top of the logic from #39826 to account for interpolation
characters inside quotes.
Fixes#39601.
PR Close#40267
Currently the compiler treats something like `{{ '{{a}}' }}` as a nested
binding and throws an error, because it doesn't account for quotes
when it looks for binding characters. These changes add a bit of
logic to skip over text inside quotes when parsing.
Fixes#39601.
PR Close#39826
When parsing for i18n messages, interpolated strings are
split into `Text` and `Placeholder` pieces. The method that
does this `_visitTextWithInterpolation()` was becoming too
complex. This commit refactors that method along with some
associated functions that it uses.
PR Close#39717
Though we currently have the knowledge of where the `key` for an
event binding appears during parsing, we do not propagate this
information to the output AST. This means that once we produce the
template AST, we have no way of mapping a template position to the key
span alone. The best we can currently do is map back to the
`sourceSpan`. This presents problems downstream, specifically for the
language service, where we cannot provide correct information about a
position in a template because the AST is not granular enough.
This is essentially identical to the change from #38898, but for event
bindings rather than input bindings.
PR Close#39609
Currently expressions `$event.foo()` and `this.$event.foo()`, as well as `$any(foo)` and
`this.$any(foo)`, are treated as the same expression by the compiler, because `this` is considered
the same implicit receiver as when the receiver is omitted. This introduces the following issues:
1. Any time something called `$any` is used, it'll be stripped away, leaving only the first parameter.
2. If something called `$event` is used anywhere in a template, it'll be preserved as `$event`,
rather than being rewritten to `ctx.$event`, causing the value to undefined at runtime. This
applies to listener, property and text bindings.
These changes resolve the first issue and part of the second one by preserving anything that
is accessed through `this`, even if it's one of the "special" ones like `$any` or `$event`.
Furthermore, these changes only expose the `$event` global variable inside event listeners,
whereas previously it was available everywhere.
Fixes#30278.
PR Close#39323
This commit handles the following cases:
- incomplete pipes in a pipe chain
- incomplete arguments in a pipe chain
- incomplete arguments provided to a pipe
- nested pipes
The idea is to unconditionally recover on the presence of a pipe, which
should be okay because expression parsing can be independently between
pipes.
PR Close#39437
There is no actionable change in this commit other than to pretty-print
EOF tokens. Actual parsing of unterminated pipes is already supported,
this just adds a test for it.
Part of #38596
PR Close#39113
Prior to this change, expressions within ICUs would have a source span
corresponding with the whole ICU. This commit narrows down the source
spans of these expressions to the exact location in the source file, as
a prerequisite for reporting type check errors within these expressions.
PR Close#39072
This patch refactors the interpolation parser to do so iteratively
rather than using a regex. Doing so prepares us for supporting granular
recovery on poorly-formed interpolations, for example when an
interpolation does not terminate (`{{ 1 + 2`) or is not terminated
properly (`{{ 1 + 2 {{ 2 + 3 }}`).
Part of #38596
PR Close#38977
This patch adds support for recovering well-formed (and near-complete)
ASTs for semantically malformed keyed reads and keyed writes. See the
added tests for details on the types of semantics we can now recover;
in particular, notice that some assumptions are made about the form of
a keyed read/write intended by a user. For example, in the malformed
expression `a[1 + = 2`, we assume that the user meant to write a binary
expression for the key of `a`, and assign that key the value `2`. In
particular, we now parse this as `a[1 + <empty expression>] = 2`. There
are some different interpretations that can be made here, but I think
this is reasonable.
The actual changes in the parser code are fairly minimal (a nice
surprise!); the biggest addition is a `writeContext` that marks whether
the `=` operator can serve as a recovery point after error detection.
Part of #38596
PR Close#39004
Though we currently have the knowledge of where the `key` for an
attribute binding appears during parsing, we do not propagate this
information to the output AST. This means that once we produce the
template AST, we have no way of mapping a template position to the key
span alone. The best we can currently do is map back to the
`sourceSpan`. This presents problems downstream, specifically for the
language service, where we cannot provide correct information about a
position in a template because the AST is not granular enough.
PR Close#38898
The expression parser will split the expression up at the interpolation markers
into expressions and static strings. This commit also captures the positions of
these strings in the expression to be used in source-mapping later.
PR Close#38645
Prior to this change, the unary + and - operators would be parsed as `x - 0`
and `0 - x` respectively. The runtime semantics of these expressions are
equivalent, however they may introduce inaccurate template type checking
errors as the literal type is lost, for example:
```ts
@Component({
template: `<button [disabled]="isAdjacent(-1)"></button>`
})
export class Example {
isAdjacent(direction: -1 | 1): boolean { return false; }
}
```
would incorrectly report a type-check error:
> error TS2345: Argument of type 'number' is not assignable to parameter
of type '-1 | 1'.
Additionally, the translated expression for the unary + operator would be
considered as arithmetic expression with an incompatible left-hand side:
> error TS2362: The left-hand side of an arithmetic operation must be of
type 'any', 'number', 'bigint' or an enum type.
To resolve this issues, the implicit transformation should be avoided.
This commit adds a new unary AST node to represent these expressions,
allowing for more accurate type-checking.
Fixes#20845Fixes#36178
PR Close#37918
Builds on top of #34655 to support more cases that could be using a pipe inside host bindings (e.g. ternary expressions or function calls).
Fixes#37610.
PR Close#37883
ASTs for property read and method calls contain information about
the entire span of the expression, including its receiver. Use cases
like a language service and compile error messages may be more
interested in the span of the direct identifier for which the
expression is constructed (i.e. an accessed property). To support this,
this commit adds a `nameSpan` property on
- `PropertyRead`s
- `SafePropertyRead`s
- `PropertyWrite`s
- `MethodCall`s
- `SafeMethodCall`s
The `nameSpan` property already existed for `BindingPipe`s.
This commit also updates usages of these expressions' `sourceSpan`s in
Ngtsc and the langauge service to use `nameSpan`s where appropriate.
PR Close#36826
This commit propagates the `sourceSpan` and `valueSpan` of a `VariableBinding`
in a microsyntax expression to `ParsedVariable`, and subsequently to
View Engine Variable AST and Ivy Variable AST.
Note that this commit does not propagate the `keySpan`, because it involves
significant changes to the template AST.
PR Close#36047
This commit adds fine-grained text spans to TemplateBinding for microsyntax expressions.
1. Source span
By convention, source span refers to the entire span of the binding,
including its key and value.
2. Key span
Span of the binding key, without any whitespace or keywords like `let`
The value span is captured by the value expression AST.
This is part of a series of PRs to fix source span mapping in microsyntax expression.
For more info, see the doc https://docs.google.com/document/d/1mEVF2pSSMSnOloqOPQTYNiAJO0XQxA1H0BZyESASOrE/edit?usp=sharing
PR Close#35897
TemplateAst values are currently typed as the base class AST, but they
are actually constructed with ASTWithSource. Type them as such, because
ASTWithSource gives more information about the consumed expression AST
to downstream customers (namely, the expression AST source).
Unblocks #35271
PR Close#35892
This commit removes the `NullAstVisitor` and `visitAstChildren` exported
from `packages/compiler/src/expression_parser/ast.ts` because they
contain duplicate and buggy implementation, and their use cases could be
sufficiently covered by `RecursiveAstVisitor` if the latter implements the
`visit` method. This use case is only needed in the language service.
With this change, any visitor that extends `RecursiveAstVisitor` could
just define their own `visit` function and the parent class will behave
correctly.
A bit of historical context:
In language service, we need a way to tranverse the expression AST in a
selective manner based on where the user's cursor is. This means we need a
"filtering" function to decide which node to visit and which node to not
visit. Instead of refactoring `RecursiveAstVisitor` to support this,
`visitAstChildren` was created. `visitAstChildren` duplicates the
implementation of `RecursiveAstVisitor`, but introduced some bugs along
the way. For example, in `visitKeyedWrite`, it visits
```
obj -> key -> obj
```
instead of
```
obj -> key -> value
```
Moreover, because of the following line
```
visitor.visit && visitor.visit(ast, context) || ast.visit(visitor, context);
```
`visitAstChildren` visits every node *twice*.
PR Close#35619
Pipes in host binding expressions are not supported in View Engine and Ivy, but in some more complex cases (like `(value | pipe) === true`) compiler was not reporting errors. This commit extends Ivy logic to detect pipes in host binding expressions and throw in cases bindings are present. View Engine behavior remains the same.
PR Close#34655
In the past, only the starting index of an expression Token has been
recorded, so a parser could demarkate the span of a token only by the
start locations of two tokens. This may lead to trailing whitespace
being included in the token span:
```html
{{ token1 + token2 }}
^^^^^^^^^ recorded span of `token1`
```
It's also not enough for a parser to determine the end of a token by
adding the length of the token value to the token's start location,
because lexed expression values may not exactly reflect the source code.
For example, `"d\\"e"` is lexed as a string token whose value is `d"e`.
Instead, this commit adds a `end` field to expression tokens. `end`
is one past the last index of the token source code. This will enable a
parser to determine the span of a token just by looking at that token.
This is a breaking change because the contructor interface of `Token`
has changed.
Part of #33477.
PR Close#33549
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
Expressions in an inline template binding are improperly recorded as
spaning an offset calculated from the start of the template binding
attribute key, whereas they should be calculated from the start of the
attribute value, which contains the actual binding AST.
PR Close#31813
The template parser has a certain interpolation config associated with
it and builds a regular expression each time it needs to extract the
interpolations from an input string. Since the interpolation config is
typically the default of `{{` and `}}`, the regular expression doesn't
have to be recreated each time. Therefore, this commit creates only a
single regular expression instance that is used for the default
configuration.
In a large compilation unit with big templates, computing the regular
expression took circa 275ms. This change reduces this to effectively
zero.
PR Close#34332
