Rather than expecting that a position in a template only targets a
single node, this commit adjusts the approach to account for two way
bindings. In particular, we attempt to get definitions for each targeted
node and then return the combination of all results, or `undefined` if
none of the target nodes had definitions.
PR Close#40185
Adjust the visitor logic of the template target as well as the
consumption of the visitor result to account for two-way bindings.
This sets up downstream consumers for being able to handle the
possibility of a template position that targets both an input and an
output.
PR Close#40185
The current template target implementation only allows a way to
represent the template position as targeting a single node in the
template AST. However, there is at least one case (banana-in-a-box)
where a given template position refers to two template targets.
This commit expands the contexts that the `TemplateTarget` can return to
include support for the banana-in-a-box syntax, which has two logically
targetted AST nodes given a position within the `keySpan` of the
binding.
PR Close#40185
This commit ensures that the template type checker returns symbols for
all outputs if a template output listener binds to more than one.
PR Close#40144
We need a means to preserve typecheck files when a project is reloaded,
otherwise the Ivy compiler will throw an error when it's unable to find
them. This commit implements `getExternalFiles()` called by the langauge
server to achieve this goal.
For more info see https://github.com/angular/vscode-ng-language-service/issues/1030
PR Close#40162
`ts.server.ServerHost.resolvePath()` is different from Angular's
`FileSystem.resolve()` because the signature of the former is
```ts
resolvePath(path: string): string; // ts.server.ServerHost
```
whereas the signature of the latter is
```ts
resolve(...paths: string[]): AbsoluteFsPath; // FileSystem on compiler-cli
```
The current implementation calls `path.join()` to concatenate all the input
paths and pass the result to `ts.server.ServerHost.resolvePath()`, but doing
so results in filenames like
```
/foo/bar/baz/foo/bar/baz/tsconfig.json
```
if both input paths are absolute.
`ts.server.ServerHost` should not be used to implement the
`resolve()` method expected by Angular's `FileSystem`.
We should use Node's `path.resolve()` instead, which will correctly collapse
the absolute paths.
Fix https://github.com/angular/vscode-ng-language-service/issues/1035
PR Close#40242
Given the template
`<div (click)="doSomething($event)"></div>`
If you request references for the `$event`, the results include both `$event` and `(click)="doSomething($event)"`.
This happens because in the TCB, `$event` is passed to the `subscribe`/`addEventListener`
function as an argument. So when we ask typescript to give us the references, we
get the result from the usage in the subscribe body as well as the one passed in as an argument.
This commit adds an identifier to the `$event` parameter in the TCB so
that the result returned from `getReferencesAtPosition` can be
identified and filtered out.
fixes#40157
PR Close#40158
This commit fixes an issue in the ivy native language service
that caused the logic that finds a target node given a template
position to throw away the results. This happened because the
source span of a variable node in the shorthand structural
directive syntax (i.e. `*ngIf=`) included the entire binding.
The result was that we would add the variable node to the path and then
later detect that the cursor was outside the key and value spans and
throw away the whole result. In general, we do this because we do not
want to show information when the cursor is between a key/value
(`inputA=¦"123"`). However, when using the shorthand syntax, we run into
the situation where we can match an `AttributeBinding` as well as the
vaariable in `*ngIf="som¦eValue as myLocalVar"`. This commit updates the
visitor to retain enough information in the visit path to throw away
invalid targets but keep valid ones if there were multiple results on a
`t.Element` or `t.Template`.
PR Close#40239
Durring analysis we find template parse errors. This commit changes
where the type checking context stores the parse errors. Previously, we
stored them on the AnalysisOutput this commit changes the errors to be
stored on the TemplateData (which is a property on the shim). That way,
the template parse errors can be grouped by template.
Previously, if a template had a parse error, we poisoned the module and
would not procede to find typecheck errors. This change does not poison
modules whose template have typecheck errors, so that ngtsc can emit
typecheck errors for templates with parse errors.
Additionally, all template diagnostics are produced in the same place.
This allows requesting just the template template diagnostics or just
other types of errors.
PR Close#40026
This comit adds support for autocompletion of attributes that create
structural directives. Such completions differ from those of normal
attributes, as the structural directive syntax creates a synthetic
<ng-template> node which has different attributes from the main element.
PR Close#40032
This commit adds attribute completion to the Language Service. It completes
from 3 sources:
1. inputs/outputs of directives currently present on the element
2. inputs/outputs/attributes of directives in scope for the element, that
would become present if the input/output/attribute was added
3. DOM properties and attributes
We distinguish between completion of a property binding (`[foo|]`) and a
completion in an attribute context (`foo|`). For the latter, bindings to
the attribute are offered, as well as a property binding which adds the
square bracket notation.
To determine hypothetical matches (directives which would become present if
a binding is added), directives in scope are scanned and matched against a
hypothetical version of the element which has the attribute.
PR Close#40032
This commit expands the autocompletion capabilities of the language service
to include element tag names. It presents both DOM elements from the Angular
DOM schema as well as any components (or directives with element selectors)
that are in scope within the template as options for completion.
PR Close#40032
This commit extends the template targeting system, which determines the node
being referenced given a template position, to return additional context if
needed about the particular aspect of the node to which the position refers.
For example, a position pointing to an element node may be pointing either
to its tag name or to somewhere in the node body. This is the difference
between `<div|>` and `<div foo | bar>`.
PR Close#40032
Projects opened in the LS are often larger in scope than the compilation
units seen by the compiler when actually building. For example, in the LS
it's not uncommon for the project to include both application as well as
test files. This can create issues when the combination of files results
in errors that are not otherwise present - for example, if test files
have inline NgModules that re-declare components (a common Angular pattern).
Such code is valid when compiling the app only (test files are excluded, so
only one declaration is seen by the compiler) or when compiling tests only
(since tests run in JIT mode and are not seen by the AOT compiler), but when
both sets of files are mixed into a single compilation unit, the compiler
sees the double declaration as an error.
This commit attempts to mitigate the problem by forcing the compiler flag
`compileNonExportedClasses` to `false` in a LS context. When tests contain
duplicate declarations, often such declarations are inline in specs and not
exported from the top level, so this flag can be used to greatly improve the
IDE experience.
PR Close#40092
When `checkTypeOfPipes` is set to `false`, the configuration is meant to
ignore the signature of the pipe's `transform` method for diagnostics.
However, we still should produce some information about the pipe for the
`TemplateTypeChecker`. This change refactors the returned symbol for
pipes so that it also includes information about the pipe's class
instance as it appears in the TCB.
PR Close#39555
The TCB utility functions used to find nodes in the TCB are currently
configured to ignore results when an ignore marker is found. However,
these ignore markers are only meant to affect diagnostics requests. The
Language Service may have a need to find nodes with diagnostic ignore
markers. The most common example of this would be finding references for
generic directives. The reference appears to the generic directive's
class appears on the type ctor in the TCB, which is ignored for
diagnostic purposes.
These functions should only skip results when the request is in the
context of a larger request for _diagnostics_. In all other cases, we
should get matches, even if a diagnostic ignore marker is encountered.
PR Close#40071
This commit adds the ability to find references for a directive or component
from within a component template. That is, you can find component references
from the element tag `<my-c|omp></my-comp>` (where `|` is the cursor position)
as well as find references for directives that match a given attribute
`<div d|ir></div>`.
PR Close#40054
If we've already identified that we are within a `keySpan` of a node, we
exit the visitor logic early. It can be the case that we have two nodes
which technically match a given location when the end span of one node
touches the start of the keySpan for the candidate node. Because
our `isWithin` logic is inclusive on both ends, we can match both nodes.
This change exits the visitor logic once we've identified a node where
the position is within its `keySpan`.
PR Close#40047
The visitor has a check in it with the goal of preventing the structural directive
parent elements from matching when we have already found the candidate we want.
However, this code did not check to ensure that it was looking at the correct
type of node for this case and was evaluating this logic in places it shouldn't.
This special check can be more easily done by simply not traversing the
template children if we've already found a candidate on the template
node itself.
PR Close#40047
This commit adds support to the Language Service for autocompletion within
expression contexts. Specifically, this is auto completion of property reads
and method calls, both in normal and safe-navigational forms.
PR Close#39727
When `checkTypeOfOutputEvents` is `false`, we still need to produce the access
to the `EventEmitter` so the Language Service can still get the
type information about the field. That is, in a template `<div
(output)="handle($event)"`, we still want to be able to grab information
when the cursor is inside the "output" parens. The flag is intended only
to affect whether the compiler produces diagnostics for the inferred
type of the `$event`.
PR Close#39515
Rather than returning `null`, we can provide some useful information to the Language Service
by returning a symbol for the `addEventListener` function call when the consumer
of a binding as an element.
PR Close#39312
When the compiler option `checkTypeOfAttributes` is `false`, we should
still be able to produce type information from the
`TemplateTypeChecker`. The current behavior ignores all attributes that
map to directive inputs. This commit includes those attribute bindings
in the TCB but adds the "ignore for diagnostics" marker so they do not
produce errors. This way, consumers of the TTC (the Language Service)
can still get valid information about these attributes even when the
user has configured the compiler to not produce diagnostics/errors for them.
PR Close#39537
This commit adds support in the Ivy Language Service for autocompletion in a
global context - e.g. a {{foo|}} completion.
Support is added both for the primary function `getCompletionsAtPosition` as
well as the detail functions `getCompletionEntryDetails` and
`getCompletionEntrySymbol`. These latter operations are not used yet as an
upstream change to the extension is required to advertise and support this
capability.
PR Close#39250
When the compiler is invoked via ngc or the Angular CLI, its APIs are used
under the assumption that Angular analysis/diagnostics are only requested if
the program has no TypeScript-level errors. A result of this assumption is
that the incremental engine has not needed to resolve changes via its
dependency graph when the program contained broken imports, since broken
imports are a TypeScript error.
The Angular Language Service for Ivy is using the compiler as a backend, and
exercising its incremental compilation APIs without enforcing this
assumption. As a result, the Language Service has run into issues where
broken imports cause incremental compilation to fail and produce incorrect
results.
This commit introduces a mechanism within the compiler to keep track of
files for which dependency analysis has failed, and to always treat such
files as potentially affected by future incremental steps. This is tested
via the Language Service infrastructure to ensure that the compiler is doing
the right thing in the case of invalid imports.
PR Close#39923
To avoid overwhelming a user with secondary diagnostics that derive from a
"root cause" error, the compiler has the notion of a "poisoned" NgModule.
An NgModule becomes poisoned when its declaration contains semantic errors:
declarations which are not components or pipes, imports which are not other
NgModules, etc. An NgModule also becomes poisoned if it imports or exports
another poisoned NgModule.
Previously, the compiler tracked this poisoned status as an alternate state
for each scope. Either a correct scope could be produced, or the entire
scope would be set to a sentinel error value. This meant that the compiler
would not track any information about a scope that was determined to be in
error.
This method presents several issues:
1. The compiler is unable to support the language service and return results
when a component or its module scope is poisoned.
This is fine for compilation, since diagnostics will be produced showing the
error(s), but the language service needs to still work for incorrect code.
2. `getComponentScopes()` does not return components with a poisoned scope,
which interferes with resource tracking of incremental builds.
If the component isn't included in that list, then the NgModule for it will
not have its dependencies properly tracked, and this can cause future
incremental build steps to produce incorrect results.
This commit changes the tracking of poisoned module scopes to use a flag on
the scope itself, rather than a sentinel value that replaces the scope. This
means that the scope itself will still be tracked, even if it contains
semantic errors. A test is added to the language service which verifies that
poisoned scopes can still be used in template type-checking.
PR Close#39923
This commit adds "find references" functionality to the Ivy integrated
language service. The basic approach is as follows:
1. Generate shims for all files to ensure we find references in shims
throughout the entire program
2. Determine if the position for the reference request is within a
template.
* Yes, it is in a template: Find which node in the template AST the
position refers to. Then find the position in the shim file for that
template node. Pass the shim file and position in the shim file along
to step 3.
* No, the request for references was made outside a template: Forward
the file and position to step 3.
3. (`getReferencesAtTypescriptPosition`): Call the native TypeScript LS
`getReferencesAtPosition`. For each reference that is in a shim file, map those
back to a template location, otherwise return it as-is.
PR Close#39768
language_service_adapter_spec was renamed to adapters_spec as part of
d39c4bbe37, but I failed to check in
adapters_spec, thereby just deleting the spec. This reintroduces it.
PR Close#39742
Currently `readConfiguration` relies on the file system to perform disk
utilities needed to read determine a project configuration file and read
it. This poses a challenge for the language service, which would like to
use `readConfiguration` to watch and read configurations dependent on
extended tsconfigs (#39134). Challenges are at least twofold:
1. To test this, the langauge service would need to provide to the
compiler a mock file system.
2. The language service uses file system utilities primarily through
TypeScript's `Project` abstraction. In general this should correspond
to the underlying file system, but it may differ and it is better to
go through one channel when possible.
This patch alleviates the concern by directly providing to the compiler
a "ParseConfigurationHost" with read-only "file system"-like utilties.
For the language service, this host is derived from the project owned by
the language service.
For more discussion see
https://docs.google.com/document/d/1TrbT-m7bqyYZICmZYHjnJ7NG9Vzt5Rd967h43Qx8jw0/edit?usp=sharing
PR Close#39619
This commit adds new language service testing infrastructure which allows
for in-memory testing. It solves a number of issues with the previous
testing infrastructure that relied on a single integration project across
all of the tests, and also provides for much faster builds by using
the compiler-cli's mock versions of @angular/core and @angular/common.
A new `LanguageServiceTestEnvironment` class (conceptually mirroring the
compiler-cli `NgtscTestEnvironment`) controls setup and execution of tests.
The `FileSystem` abstraction is used to drive a `ts.server.ServerHost`,
which backs the language service infrastructure.
Since many language service tests revolve around the template, the API is
currently optimized to spin up a "skeleton" project and then override its
template for each test.
The existing Quick Info tests (quick_info_spec.ts) were ported to the new
infrastructure for validation. The tests were cleaned up a bit to remove
unnecessary initializations as well as correct legitimate template errors
which did not affect the test outcome, but caused additional validation of
test correctness to fail. They still utilize a shared project with all
fields required for each individual unit test, which is an anti-pattern, but
new tests can now easily be written independently without relying on the
shared project, which was extremely difficult previously. Future cleanup
work might refactor these tests to be more independent.
PR Close#39594
In preparation for in-memory testing infrastructure, the existing Ivy
language service tests are moved to a `legacy` directory. These existing
tests rely on a single integration project in `test/project/app`, which
presents a number of challenges:
* adding extra fields/properties to the integration project for one test
can cause others to fail/flake.
* it's especially difficult to test any cases that require introducing
intentional errors, as those tend to break other tests.
* tests load files from disk, which is slower.
* tests rely on the real built versions of @angular/core and
@angular/common, which makes them both slow to build and require rebuilds
on every compiler change.
* tests share a single tsconfig.json, making it extremely difficult to test
how the language service handles different configuration scenarios (e.g.
different type-checking flags).
PR Close#39594
Similar to #39613, #39609, and #38898, we should store the `keySpan` for
Reference nodes so that we can accurately map from a template node to a
span in the original file. This is most notably an issue at the moment
for directive references `#ref="exportAs"`. The current behavior for the
language service when requesting information for the reference
is that it will return a text span that results in
highlighting the entire source when it should only highlight "ref" (test
added for this case as well).
PR Close#39616
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
Similar to #39609 and #38898, though we currently have the knowledge of where the key for an
attribute 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#39613
Rather than re-reading component metadata that was already interpreted
by the Ivy compiler, the Language Service should instead use the
compiler APIs to get information it needs about the metadata.
PR Close#39476
This commit takes the `HybridVisitor` in the language service and gives it
the ability to return not just a node but the template context in which it
appears. In the future, more context regarding where a node appears in the
template might become necessary (ex: the microsyntax container for binding
nodes), and this refactoring enables that.
In the process, `HybridVisitor` is renamed and the concept of a
`TemplateTarget` interface is introduced to contain the results of this
operation.
PR Close#39505
Currently render3's `parseTemplate` throws away the parsed AST and
returns an empty list of HTML nodes if HTML->R3 translation failed. This
is not preferrable in some contexts like that of a language service,
where we would like a well-formed AST even if it is has errors.
PR Close#39413
Constructing a project service is expensive. Making it a singleton could
speed up tests considerably.
On my MacBook Pro, test execution went from 24.4s to 14.5s (~40% improvement).
PR Close#39308
Test harness `setup()` is expensive, in the order of ~2.5 seconds.
We could speed up `fit()` tests considerably if `setup()` is wrapped
in `beforeAll()` to avoid running it unnecessarily.
PR Close#39305
This commit enables the Ivy Language Service to 'go to definition' of a
templateUrl or styleUrl, which would jump to the template/style file
itself.
PR Close#39202
When an input name is part of the directive selector, it would be good to return the directive as well
when performing 'go to definition' or 'go to type definition'. As an example, this would allow
'go to type definition' for ngIf to take the user to the NgIf directive.
'Go to type definition' would otherwise return no results because the
input is a generic type. This would also be the case for all primitive
input types.
PR Close#39243
This commit fixes a bug in which a new Ivy Compiler is created every time
language service receives a new request. This is not needed if the
`ts.Program` has not changed.
A new class `CompilerFactory` is created to manage Compiler lifecycle and
keep track of template changes so that it knows when to override them.
With this change, we no longer need the method `getModifiedResourceFile()`
on the adapter. Instead, we call `overrideComponentTemplate` on the
template type checker.
This commit also changes the incremental build strategy from
`PatchedIncrementalBuildStrategy` to `TrackedIncrementalBuildStrategy`.
PR Close#39231
For directives/components, it would be generally more appropriate for
"go to type definition" to be the function which navigates to the class
definition. However, for a better user experience, we should do this
for "go to definition" as well.
PR Close#39228
This PR enables `getSemanticDiagnostics()` to be called on external templates.
Several changes are needed to land this feature:
1. The adapter needs to implement two additional methods:
a. `readResource()`
Load the template from snapshot instead of reading from disk
b. `getModifiedResourceFiles()`
Inform the compiler that external templates have changed so that the
loader could invalidate its internal cache.
2. Create `ScriptInfo` for external templates in MockHost.
Prior to this, MockHost only track changes in TypeScript files. Now it
needs to create `ScriptInfo` for external templates as well.
For (1), in order to make sure we don't reload the template if it hasn't
changed, we need to keep track of its version. Since the complexity has
increased, the adapter is refactored into its own class.
PR Close#39065
Fixed a boolean logic error that prevented hybrid visitor from returning
undefined when a variable does not have value and cursor is not in the
key span.
PR Close#39061
It used to be the case that all microsyntax bindings share the same source
span, so the second bound attribute would overwrite the first.
This has been fixed in #39036, this case is added to prevent regression.
PR Close#39062
For the following example, the cursor is between `keySpan` and `valueSpan`
of the `BoundAttribute`.
```html
<test-cmp [foo]¦="bar"></test-cmp>
```
Our hybrid visitor will return `Element`in this case, which is the parent
node of the `BoundAttribute`.
This is because we only look at the `keySpan` and `valueSpan`, and not
the source span. The last element in the AST path is `Element`, so it gets
returned.
In this PR, I propose fixing this by adding a sentinel value `undefined`
to the AST path to signal that we've found a source span but the cursor is
neither in the key span nor the value span.
PR Close#38995
The keySpan in bound attributes provides more fine-grained location information and can be used
to disambiguate multiple bound attributes in a single microsyntax binding. Previously,
this case could not distinguish between the two different attributes because
the sourceSpans were identical and valueSpans would not match if the cursor
was located in a key.
PR Close#38955
In a microsyntax expressions, some attributes are not bound after
desugaring. For example,
```html
<div *ngFor="let item of items">
</div>
```
gets desugared to
```html
<ng-template ngFor let-items [ngForOf]="items">
</ngtemplate>
```
In this case, `ngFor` should be a literal attribute with no RHS value.
Therefore, its source span should be just the `keySpan` and not the
source span of the original template node.
This allows language service to precisely pinpoint different spans in a
microsyntax to provide accurate information.
PR Close#38766
In the test project there are no longer reference markers and location
markers, so there's no need to "pre-process" the source files to remove
them. This will make the Ivy tests cleaner and faster.
PR Close#38777
Previously this interface was mostly stored in compiler-cli, but it
contains some properties that would be useful for compiling the
"declare component" prelink code.
This commit moves some of the interface over to the compiler
package so that it can be referenced there without creating a
circular dependency between the compiler and compiler-cli.
PR Close#38594
In many testing scenarios, there is a common pattern:
1. Overwrite template (inline or external)
2. Find cursor position
3. Call one of language service APIs
4. Inspect spans in result
In order to faciliate this pattern, this commit refactors
`MockHost.overwrite()` and `MockHost.overwriteInlineTemplate()` to
allow a faux cursor symbol `¦` to be injected into the template, and
the methods will automatically remove it before updating the script snapshot.
Both methods will return the cursor position and the new text without
the cursor symbol.
This makes testing very convenient. Here's a typical example:
```ts
const {position, text} = mockHost.overwrite('template.html', `{{ ti¦tle }}`);
const quickInfo = ngLS.getQuickInfoAtPosition('template.html', position);
const {start, length} = quickInfo!.textSpan;
expect(text.substring(start, start + length)).toBe('title');
```
PR Close#38552
This commit introduces two visitors, one for Template AST and the other
for Expression AST to allow us to easily find the node that most closely
corresponds to a given cursor position.
This is crucial because many language service APIs take in a `position`
parameter, and the information returned depends on how well we can find
a good candidate node.
In View Engine implementation of language service, the search for the node
and the processing of information to return the result are strongly coupled.
This makes the code hard to understand and hard to debug because the stack
trace is often littered with layers of visitor calls.
With this new feature, we could test the "searching" part separately and
colocate all the logic (aka hacks) that's required to retrieve an accurate
span for a given node.
Right now, only the most "narrow" node is returned by the main exported
function `findNodeAtPosition`. If needed, we could expose the entire AST
path, or expose other methods to provide more context for a node.
Note that due to limitations in the template AST interface, there are
a few known cases where microsyntax spans are not recorded properly.
This will be dealt with in a follow-up PR.
PR Close#38540
Now that Ivy compiler has a proper `TemplateTypeChecker` interface
(see https://github.com/angular/angular/pull/38105) we no longer need to
keep the temporary compiler implementation.
The temporary compiler was created to enable testing infrastructure to
be developed for the Ivy language service.
This commit removes the whole `ivy/compiler` directory and moves two
functions `createTypeCheckingProgramStrategy` and
`getOrCreateTypeCheckScriptInfo` to the `LanguageService` class.
Also re-enable the Ivy LS test since it's no longer blocking development.
PR Close#38310
This commit disables the tests for Ivy version of language service on CI
because the compiler APIs are not yet stable, so language service should
not assert against its behavipr.
PR Close#37348
This commit adds a Compiler interface that wraps the actual ngtsc
compiler. The language-service specific compiler manages multiple
typecheck files using the Project interface, creating and adding
ScriptInfos as necessary.
This commit also adds `overrideInlineTemplate()` method to the mock
service so that we could test the Compiler diagnostics feature.
PR Close#36930
Add a mechanism to replace file contents for a specific file. This
allows us to write custom test scenarios in code without modifying the
test project.
Since we are no longer mocking the language service host, the file
overwrite needs to happen via the project service.
Project service manages a set of script infos, and overwriting the files
is a matter of updating the relevant script infos.
Note that the actual project service is wrapped inside a Mock Service.
Tests should not have direct access to the project service. All
manipulations should take place via the Mock Service.
The MockService provides a `reset()` method to undo temporary overwrites
after each test.
PR Close#36923
Parse Angular compiler options in Angular language service.
In View Engine, only TypeScript compiler options are read, Angular
compiler options are not. With Ivy, there could be different modes of
compilation, most notably how strict the templates should be checked.
This commit makes the behavior of language service consistent with the
Ivy compiler.
PR Close#36922
This commit adds a new mock host for testing the ivy language service.
Unlike the existing mock_host which mocks the LanguageServiceHost, the
Ivy mock host mocks just the filesystem interface, aka ts.ServerHost.
This is because Ivy language service requires an actual Project to
perform operations like adding synthetic typecheck files to the project,
and by extension, to the ts.Program. These requirements make the existing
mock host unsuitable to be reused.
This new testing structure also improves test performance, because the
old mock host copies (it actually creates symlinks, but still that's
relatively expensive due to the sheer number of files involved) all
@angular/* packages along with the typescript package to a temporary
node_modules directory. This is done every time setup() is called.
Instead, this new mock host just loads them from a pre-determined path
in Bazel runfiles.
PR Close#36879
Andrew Scott
Keen Yee Liau
Zach Arend
Alex Rickabaugh
ayazhafiz
JoostK
Keen Yee Liau
Pete Bacon Darwin
Joey Perrott