Currently the listener side two-way listeners are parsed by appending `=$event` to the raw expression. This is problematic, because:
1. It can interfere with other expressions (see #37809).
2. It can lead to confusing error messages because users will see code that they didn't write.
3. It doesn't allow us to further manipulate the expression.
These changes remove the logic that appends `=$event` to resolve the issue. There's also some new logic that checks the expression after it has been parsed to ensure that the result is an assignable expression.
Subsequent commits will update the code that emits the expression to add back the `$event` assignment where it's needed.
PR Close#54154
When blocks were initially implemented, they were represented as containers in the i18n AST. This is problematic, because block affect the structure of the message.
These changes introduce a new `BlockPlaceholder` AST node and integrate it into the i18n pipeline. With the new node blocks are represented with the `START_BLOCK_<name>` and `CLOSE_BLOCK_<name>` placeholders.
PR Close#52958
A lot of our tests are wrapped in `{}` which serves no purpose, aside from increasing the nesting level and, in some cases, causing confusion. The braces appear to be a leftover from a time when all tests were wrapped in a `function main() {}`. The function declaration was removed in #21053, but the braces remained, presumably because it was easier to search&replace for `function main()`, but not to remove the braces at the same time.
PR Close#52239
Since we generate a `.mjs` file as entry-point for jasmine tests,
a couple of issues prevented the transitive dependencies from
bootstrap targets to be brought in (causing resolution errors):
1. The `_files` (previously `_esm2015`) targets are no longer needed,
and they also miss all the information on runfiles.
2. The aspect for computing linker mappings does not respect the
`bootstrap` attribute from the `spec_entrypoint` so we manually
add the extract ESM output targets (this rule works with the aspect
and forwards linker mappings).
PR Close#48521
For every `ts_library` target we expose a shorthand that grants
access to the JS files because `DefaultInfo` of a ts library
only exposes the `.d.ts` files.
We rename this away from `es2015` since in practice it's a much
higher target these days. Additionally we no longer use the devmode
output but rather use the prodmode output which has the explicit
`.mjs` output- compatible with ESM.
PR Close#48521
In #39004 some logic was introduced that tries to recover invalid expressions by treating the `=` token as a recovery point. It works by skipping ahead to the next recovery point inside the `skip` method which is called whenever an error is reported. This can lead to an infinite loop inside the `parseChain` method which assumes that reporting an error would've skipped over the token, but that won't happen since the `=` token is a recovery point. These changes resolve the infinite loop by breaking the loop if `error` didn't skip to a different token after the error was reported.
Fixes#47131.
PR Close#47151
When parsing interpolations, the input string is _decoded_ from what was
in the orginal template. This means that we cannot soley rely on the input
string to compute source spans because it does not necessarily reflect
the exact content of the original template. Specifically, when there is
an HTML entity (i.e. ` `), this will show up in its decoded form
when processing the interpolation (' '). We need to compute offsets
using the original _encoded_ string.
Note that this problem only surfaces in the splitting of interpolations.
The spans to this point have already been tracked accurately. For
example, given the template ` <div></div>`, the source span for the
`div` is already correctly determined to be 6. Only when we encounter
interpolations with many parts do we run into situations where we need
to compute new spans for the individual parts of the interpolation.
PR Close#44811
For two-way-bindings that use the banana-in-a-box syntax, the compiler
synthesizes an event assignment expression from the primary expression.
It is valid for the primary expression to be terminated by the non-null
operator, however naive string substitution is used for the synthesized
expression, such that the `!` would immediately precede the `=` token,
resulting in the valid `!=` operator token. The expression would still
parse correctly but it doesn't implement the proper semantics, resulting
in incorrect runtime behavior.
Changing the expression substitution to force a space between the
primary expression and the assignment avoids this mistake, but it
uncovers a new issue. The grammar does not allow for the LHS of an
assignment to be the non-null operator, so the synthesized expression
would fail to parse. To alleviate this, the synthesized expression is
parsed with a special parser flag to allow for this syntax.
Fixes#36551
PR Close#37809
So-called "Quote expressions" were added in b6ec2387b3
to support foreign syntax to be used in Angular templates, requiring a custom
template transform to convert them somehow during compilation. Support for template
transforms was originally implemented in a43ed79ee7 but
has since been dropped. Since the compiler is not public API the quote expressions
should not have any usages anymore. Removing support for them can improve error
reporting for expressions that contain a `:`, e.g. binding to a URL without quotes:
```html
<a [href]="http://google.com">Click me</a>
```
Here, `http` would be parsed as foreign "http" quote expression with `//google.com` as
value, later reporting the error "Quotes are not supported for evaluation!" because
there was no template transform to convert that code.
Closes#40398
PR Close#44915
To make our test output i.e. devmode output more aligned
with what we produce in the NPM packages, or to be more
aligned with what Angular applications will usually consume,
the devmode output is switched from ES5 to ES2015.
Additionally various tsconfigs (outside of Bazel) have been
updated to match with the other parts of the build. The rules
are:
ES2015 for test configurations, ES2020 for actual code that will
end up being shipped (this includes the IDE-only tsconfigs).
PR Close#44505
This commit removes most tests that were designated as only covering View
Engine code. It also removes tag filters from CI and local commands to run
tests.
In a few cases (such as with the packages/compiler tests), this tag was
improperly applied, and certain test cases have been added back running in
Ivy mode.
This commit also empties `@angular/compiler/testing` as it is no longer
necessary (this is safe since compiler packages are not public API). It can
be deleted in the future.
PR Close#43884
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
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
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
The expression parser already has support for recovering on malformed
property reads, but did not have tests describing the recovered ast in
such cases. This commit adds tests to demonstrate such cases; in
particular, the recovered ast is a full PropertyRead but with an empty
property name. This is likely the most preferred option, as it does not
constrain consumers of the AST to what the property name should look
like. Furthermore, we cannot mark the property name as empty in any
other way (e.g. an EmptyExpr) because the property name, as of present,
is a string field rather than an AST itself.
Note that tokens past a malformed property read are not preserved in the
AST (for example in `foo.1234`, `1234` is not preserved in the AST).
This is because the extra tokens do not belong to the singular
expression created by the property read, and there is not a meaningful
way to interpret a secondary expression in a single parsed expression.
Part of #38596
PR Close#38998
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
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 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
