Back in #39323, I added a new `ThisReceiver` node to represent accesses done through `this` and I ended up making it inherit from `ImplicitReceiver`. The logic was that in most cases accessing through `this` was the same as the implicit access.
Over the years this has proven to not be a great idea, because no other AST nodes do this and one has to keep it in mind whenever dealing with `ImplicitReceiver`.
These changes remove the inheritance and update all of the usage sites accordingly.
When disabling `i18nPreserveSignificantWhitespaceForLegacyExtraction` I was looking at a test case with ICU messages containing leading and trailing whitespace:
```angular
<div i18n>
{apples, plural, =other {I have many apples.}}
</div>
```
This would historically generate two messages:
```javascript
const MSG_TMP = goog.getMsg('{apples, plural, =other {I have many apples.}}');
const MSG_FOO = goog.getMsg(' {$ICU} ', { 'ICU': MSG_TMP });
```
But I found that I was getting just one message:
```javascript
const MSG_TMP = goog.getMsg(' {apples, plural, =other {I have many apples.}} ');
```
This is arguably an improvement, but changed the messages and message IDs, which isn't desirable with this option. I eventually traced this back to the `isIcu` initialization in [`i18n_parser.ts`](/packages/compiler/src/i18n/i18n_parser.ts):
```typescript
const context: I18nMessageVisitorContext = {
isIcu: nodes.length == 1 && nodes[0] instanceof html.Expansion,
// ...
};
```
[`_I18nVisitor.prototype.visitExpansion`](/packages/compiler/src/i18n/i18n_parser.ts) uses this to decide whether or not to generate a sub-message for a given ICU expansion:
```typescript
if (context.isIcu || context.icuDepth > 0) {
// Returns an ICU node when:
// - the message (vs a part of the message) is an ICU message, or
// - the ICU message is nested.
const expPh = context.placeholderRegistry.getUniquePlaceholder(`VAR_${icu.type}`);
i18nIcu.expressionPlaceholder = expPh;
context.placeholderToContent[expPh] = {
text: icu.switchValue,
sourceSpan: icu.switchValueSourceSpan,
};
return context.visitNodeFn(icu, i18nIcu);
}
// Else returns a placeholder
// ICU placeholders should not be replaced with their original content but with the their
// translations.
// TODO(vicb): add a html.Node -> i18n.Message cache to avoid having to re-create the msg
const phName = context.placeholderRegistry.getPlaceholderName('ICU', icu.sourceSpan.toString());
context.placeholderToMessage[phName] = this.toI18nMessage([icu], '', '', '', undefined);
const node = new i18n.IcuPlaceholder(i18nIcu, phName, icu.sourceSpan);
return context.visitNodeFn(icu, node);
```
Note that `isIcu` is the key condition between these two cases and depends on whether or not the ICU expansion has any siblings. The introduction of `WhitespaceVisitor` to `I18nMetaVisitor` trims insignificant whitespace, including empty text nodes not adjacent to an ICU expansion (from [`WhitespaceVisitor.prototype.visitText`](/packages/compiler/src/ml_parser/html_whitespaces.ts)):
```typescript
const isNotBlank = text.value.match(NO_WS_REGEXP);
const hasExpansionSibling =
context && (context.prev instanceof html.Expansion || context.next instanceof html.Expansion);
if (isNotBlank || hasExpansionSibling) {
// Transform node by trimming it...
return trimmedNode;
}
return null; // Drop node which is empty and has no ICU expansion sibling.
```
`hasExpansionSibling` was intended to retain empty text nodes leading or trailing an ICU expansion, however `context` was `undefined`, so this check failed and the leading / trailing text nodes were dropped. This resulted in trimming the ICU text by dropping the leading / trailing whitespace nodes. Having only a single ICU expansion with no leading / trailing text nodes caused `_I18nVisitor` to initialize `isIcu` incorrectly and caused it to generate one message instead of two.
`WhitespaceVisitor` is supposed to get this context from `visitAllWithSiblings`. So the fix here is to make sure `WhitespaceVisitor` is always visited via this function which provides the required context. I updated all usage sites to make sure this context is use consistently and implemented the `WhitespaceVisitor.prototype.visit` method to throw when the context is missing to make sure we don't encounter a similar mistake in the future.
Unfortunately this broke one compliance test. Specifically the [`icu_logic/icu_only.js`](/home/douglasparker/Source/ng/packages/compiler-cli/test/compliance/test_cases/r3_view_compiler_i18n/icu_logic/icu_only.js) test which changed from generating:
```javascript
function MyComponent_Template(rf, ctx) {
if (rf & 1) {
i0.ɵɵi18n(0, 0);
}
// ...
}
```
To now generating:
```javascript
function MyComponent_Template(rf, ctx) {
if (rf & 1) {
i0.ɵɵtext(0, " ");
i0.ɵɵi18n(1, 0);
i0.ɵɵtext(2, "\n");
}
// ...
}
```
This test uses the default value `preserveWhitespaces: false` (`i18nPreserveSignificantWhitespaceForLegacyExtraction` should not affect compiled JS output, we already retain significant whitespace there). So what this indicates to me is that ICU logic is already broken because it's not preserving significant whitespace in this case. My change is probably a bug fix, but one which would affect the compiled runtime, which is not in scope here. The root cause is because using `visitAllWithSiblings` everywhere means the context is retained correctly in this case and the whitespace is leading/trailing an ICU message, therefore it is retained per the logic of `WhitespaceVisitor.prototype.visitText` I mentioned eariler.
To address this, I left one usage of `WhitespaceVisitor` using `html.visitAll` instead of `visitAllWithSiblings` to retain this bug. I has to lossen the assertion I put in `WhitespaceVisitor.prototype.visit` to make this possible, but it should still throw by default when misused, which is the important part.
PR Close#56507
This configures whether or not to preserve whitespace content when extracting messages from Angular templates in the legacy (View Engine) extraction pipeline.
This includes several bug fixes which unfortunately cannot be landed without changing message IDs in a breaking fashion and are necessary to properly trim whitespace. Instead these bug fixes are included only when the new flag is disabled.
PR Close#56507
Enables the new `@let` syntax by default.
`@let` declarations are defined as:
1. The `@let` keyword.
2. Followed by one or more whitespaces.
3. Followed by a valid JavaScript name and zero or more whitespaces.
4. Followed by the `=` symbol and zero or more whitespaces.
5. Followed by an Angular expression which can be multi-line.
6. Terminated by the `;` symbol.
Example usage:
```
@let user = user$ | async;
@let greeting = user ? 'Hello, ' + user.name : 'Loading';
<h1>{{greeting}}</h1>
```
Fixes#15280.
PR Close#56715
Introduces a new `LetDeclaration` into the Render3 AST, simiarly to the HTML AST, and adds an initial integration into the various visitors.
PR Close#55848
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
Enables the new `@` block syntax by default by removing the `enabledBlockTypes` flags. There are still some internal flags that allow special use cases to opt out of the block syntax, like during XML parsing and when compiling older libraries (see #51979).
PR Close#51994
Adds the logic to create `defer`-specific AST nodes from the generic HTML `BlockGroup` and `Block`. The logic for parsing the triggers will be in the next commit.
PR Close#51050
This commit finishes the removal of View Engine from the codebase, deleting
those pieces of @angular/compiler which were only used for VE.
Co-Authored-By: JoostK <joost.koehoorn@gmail.com>
PR Close#44368
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
After updating to a more recent version of rollup, rollup started to
complain because the `TreeParseResult` class is being re-exported
twice in the `index.ts -> public-api.ts -> compiler.ts` entry-point.
Rollup threw errors like:
```
Error: "ParseTreeResult" cannot be exported from
<..>/ml_parser/parser.mjs as it is a re-export that references itself.
```
It seems like Rollup ideally would not throw here, similar to TypeScript
which detects that these exports are the same and just dedupes them, but
it's low-effort fixing this for now and actually is a good opportunity
to make the public API a little more easy understand (when looking at
the `compiler.ts` file).
PR Close#43431
Adds a `collectCommentNodes` option on `ParseTemplateOptions` which will cause the returned `ParsedTemplate` to include an array of all html comments found in the template.
PR Close#41251
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
Now when the animation trigger output event is missing its phase value name, the `BoundEvent` will be ignored,
but it's useful for completion in language service.
PR Close#39925
Tokenized text node may have leading whitespace skipped from their
source-span. But the source-span is used to compute where there are
interpolated blocks, resulting in placeholder nodes whose source-spans
are offset by the amount of skipped characters.
This fix uses the `fullStart` location of text source-spans for computing
the source-span of placeholders, so that they are accurate.
Fixes#39195
PR Close#39486
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
This commit consolidates the options that can modify the
parsing of text (e.g. HTML, Angular templates, CSS, i18n)
into an AST for further processing into a single `options`
hash.
This makes the code cleaner and more readable, but also
enables us to support further options to parsing without
triggering wide ranging changes to code that should not
be affected by these new options. Specifically, it will let
us pass information about the placement of a template
that is being parsed in its containing file, which is essential
for accurate SourceMap processing.
PR Close#28055
This commit introduces the "t2" API, which processes parsed template ASTs
and performs a number of functions such as binding (the process of
semantically interpreting cross-references within the template) and
directive matching. The API is modeled on TypeScript's TypeChecker API,
with oracle methods that give access to collected metadata.
This work is a prerequisite for the upcoming template type-checking
functionality, and will also become the basis for a refactored
TemplateDefinitionBuilder.
PR Close#26203
