Commit Graph

5323 Commits

Author SHA1 Message Date
Greg Magolan 79a0d007b4 build: derive ts_library dep from jasmine_node_test boostrap label if it ends in `_es5` (#34589)
PR Close #34589
2020-01-10 08:32:00 -08:00
Greg Magolan 67044ef55d build: should use $(execpath) in npm_package_bin args (#34589)
This is recommended in the Bazel docs as $(location) is ambiguous and can mean either $(execpath) or $(rootpath) depending on the context.

PR Close #34589
2020-01-10 08:32:00 -08:00
Greg Magolan c3e8439954 build: add a before-all-other bootstrap script that patches require (#34589)
This removes the churn in the existing bootstrap scripts.

PR Close #34589
2020-01-10 08:32:00 -08:00
Greg Magolan 4754e495dc build: renamed "injected_scripts" target to "asset_injected_index_html" (#34589)
PR Close #34589
2020-01-10 08:32:00 -08:00
Greg Magolan da4782e67f test: handle bootstrap templated_args in jasmine_node_test defaults.bzl (#34589)
PR Close #34589
2020-01-10 08:31:59 -08:00
Greg Magolan 8042433cb0 build: update to rules nodejs 1.0.1 (#34589)
This brings in a few minor fixes including a better way to patch require for bootstrap scripts.

PR Close #34589
2020-01-10 08:31:59 -08:00
Greg Magolan 7203169c3d build: update integration/bazel & @angular/bazel schematics to rules_nodejs 1.0.0 (#34589)
For the purposes of the integration test the zone.js script & bundle script tags can just go into the source index.html itself. The purpose of the integration test is is to test @angular/bazel & ng_module & ng_package so there is no need to exercise html_insert_assets in integration/bazel.

PR Close #34589
2020-01-10 08:31:59 -08:00
Greg Magolan 9bb349e1c8 refactor: handle breaking changes in rules_nodejs 1.0.0 (#34589)
The major one that affects the angular repo is the removal of the bootstrap attribute in nodejs_binary, nodejs_test and jasmine_node_test in favor of using templated_args --node_options=--require=/path/to/script. The side-effect of this is that the bootstrap script does not get the require.resolve patches with explicitly loading the targets _loader.js file.

PR Close #34589
2020-01-10 08:31:59 -08:00
Greg Magolan 96643e7ce2 build: upgrade to io_bazel_rules_sass 1.24.0 (#34589)
PR Close #34589
2020-01-10 08:31:58 -08:00
Greg Magolan cb6ffa1211 build: upgrade to rules_nodejs 1.0.0 (first stable release) (#34589)
Brings in the fix for stamping which was preventing many targets from getting cached.

PR Close #34589
2020-01-10 08:31:58 -08:00
ayazhafiz 4d95c3d39a refactor(language-service): rename expression completions method (#34518)
This commit renames `addAttributeValuesToCompletions`, which generates
expression completions and is not exclusive to processing attributes, to
`processExpressionCompletions`. Also removes the expression completion
logic in `visitBoundText` for a call to `processExpressionCompletions`.

The conditional branch in `visitBoundText` is also removed. This branch
was added in one of the first commits to the language service
(519a324454) and appears to be
unnecessary, as the expression AST is constructed from the template
position anyway.

PR Close #34518
2020-01-10 08:31:09 -08:00
George Kalpakas c3271ac22a fix(ngcc): recognize re-exports with imported TS helpers in CommonJS and UMD (#34527)
Previously, the `CommonJsReflectionHost` and `UmdReflectionHost` would
only recognize re-exports of the form `__export(...)`. This is what
re-exports look like, when the TypeScript helpers are emitted inline
(i.e. when compiling with the default [TypeScript compiler options][1]
that include `noEmitHelpers: false` and `importHelpers: false`).

However, when compiling with `importHelpers: true` and [tslib][2] (which
is the recommended way for optimized bundles), the re-exports will look
like: `tslib_1.__exportStar(..., exports)`
These types of re-exports were previously not recognized by the
CommonJS/UMD `ReflectionHost`s and thus ignored.

This commit fixes this by ensuring both re-export formats are
recognized.

[1]: https://www.typescriptlang.org/docs/handbook/compiler-options.html
[2]: https://www.npmjs.com/package/tslib

PR Close #34527
2020-01-10 08:28:50 -08:00
crisbeto b1eb84c57e refactor(ivy): remove calls into other instructions from pipe instructions (#33714)
A while ago we made a pass through all instructions to make sure that none of them call directly into other instructions, however it seems like missed the `pipeBind*` since they still call into the pure functions. The result is that we have some unnecessary duplicated accesses of global state like `getLView` which are called twice in a row with nothing changing.

These changes move the common functionality into a shared file and make the pipe instructions call into them with the global state instead.

PR Close #33714
2020-01-10 08:27:26 -08:00
ayazhafiz 794dcb58d3 fix(language-service): do not use an i18n parser for templates (#34531)
The compiler's `I18NHtmlParser` may expand template nodes that have
internationalization metadata attached to them; for instance,

```html
<div i18n="@@i18n-el">{{}}</div>
```

gets expanded to an AST with the i18n metadata extracted and text filled
in as necessary; to the language service, the template above, as read in
the AST, now looks something like

```html
<div>{{$implicit}}</div>
```

This is undesirable for the language service because we want to preserve
the original form of the source template source code, and have
information about the original values of the template. The language
service also does not need to use an i18n parser -- we don't generate
any template output.

To fix this turns out to be as easy as moving to using a raw
`HtmlParser`.

---

A note on the testing strategy: as mentioned above, we don't need to use
an i18n parser, but we don't **not** need to use one if the parser
does not heavily modify the template AST. For this reason, the tests
target the functionality of not modifying a template with i18n metadata
rather than testing that the language service does not use an i18n parser.

---

Closes https://github.com/angular/vscode-ng-language-service/issues/272

PR Close #34531
2020-01-10 08:23:08 -08:00
Igor Minar 25eaff447a refactor(core): remove duplicate InjectableType declaration (#34679)
This duplication causes a compilation error with TypeScript 3.7

PR Close #34679
2020-01-09 16:05:20 -08:00
Paul Gschwendtner 6315acae94 fix(forms): disabled input acceptance member not properly applied (#34502)
With 5cecd97493 we intended to expand
the input type of the `disabled` input of the `NgModel` directive.
Read more about the reason for this in the actual commit message.

Currently though, the acceptance coercion member does not have any
effect. This is because the acceptance member needs to refer to the
actual input property name, and not to the public input name.
`disabled` corresponds to the `isDisabled` property.

PR Close #34502
2020-01-09 15:12:09 -08:00
Andrew Kushnir c3f14bb7a5 feat(ivy): improve `ExpressionChangedAfterChecked` error message for attributes (#34505)
This commit improves `ExpressionChangedAfterChecked` error message for attributes by including attribute name and the content of the entire expression that contains interpolation(s). In order to achieve that, metadata is now stored in `TData` array when `attribute` and `attributeInterpolate` instructions are being called (similar to `property` and `propertyInterpolate` instructions).

PR Close #34505
2020-01-09 13:47:58 -08:00
ivanwonder 181d766941 feat(language-service): completions support for template reference variables (#34363)
PR Close #34363
2020-01-09 13:45:42 -08:00
ayazhafiz 443e423b58 test(language-service): make app.component a constant (#34587)
Cleans up usages of `app.component.ts` to be a constant file variable.

PR Close #34587
2020-01-09 13:31:39 -08:00
crisbeto e48e36bde3 test(ivy): add test for class setters being invoked when not used (#34706)
Adds a test that we should make pass once the latest styling refactor has landed.

PR Close #34706
2020-01-09 13:29:16 -08:00
Pete Bacon Darwin 8815ace418 fix(ngcc): insert definitions after statement (#34677)
If a class was defined as a class expression
in a variable declaration, the definitions
were being inserted before the statment's
final semi-colon.

Now the insertion point will be after the
full statement.

Fixes #34648

PR Close #34677
2020-01-08 15:09:24 -08:00
Alex Eagle 660546d0ec refactor(bazel): remove explicit deps param to ts_compile_actions (#34665)
This was already the default. I'm working on a change in the underlying TS rules where this parameter will be replaced, so ng_module needs to change first

PR Close #34665
2020-01-08 15:08:03 -08:00
Pete Bacon Darwin 58cdc22791 fix(ngcc): handle UMD factories that do not use all params (#34660)
In some cases, where a module imports a dependency
but does not actually use it, UMD bundlers may remove
the dependency parameter from the UMD factory function
definition.

For example:

```
import * as x from 'x';
import * as z from 'z';
export const y = x;
```

may result in a UMD bundle including:

```
(function (global, factory) {
    typeof exports === 'object' && typeof module !== 'undefined' ?
        factory(exports, require('x'), require('z')) :
    typeof define === 'function' && define.amd ?
        define(['exports', 'x', 'z'], factory) :
    (global = global || self, factory(global.myBundle = {}, global.x));
}(this, (function (exports, x) { 'use strict';
...
})));
```

Note that while the `z` dependency is provide in the call,
the factory itself only accepts `exports` and `x` as parameters.

Previously ngcc appended new dependencies to the end of the factory
function, but this breaks in the above scenario. Now the new
dependencies are prefixed at the front of parameters/arguments
already in place.

Fixes #34653

PR Close #34660
2020-01-08 15:07:36 -08:00
Pete Bacon Darwin 570574df5b fix(ngcc): don't crash if symbol has no declarations (#34658)
In some cases TypeScript is unable to identify a valid
symbol for an export. In this case it returns an "unknown"
symbol, which does not reference any declarations.

This fix ensures that ngcc does not crash if such a symbol
is encountered by checking whether `symbol.declarations`
exists before accessing it.

The commit does not contain a unit test as it was not possible
to recreate a scenario that had such an "unknown" symbol in
the unit test environment. The fix has been manually checked
against that original issue; and also this check is equivalent to
similar checks elsewhere in the code, e.g.

https://github.com/angular/angular/blob/8d0de89e/packages/compiler-cli/src/ngtsc/reflection/src/typescript.ts#L309

Fixes #34560

PR Close #34658
2020-01-08 15:07:10 -08:00
crisbeto d909fb0b1f fix(ivy): ngClass not applying classes with trailing/leading spaces (#34539)
Fixes classes with trailing or leading space that are passed to `ngClass` (e.g. `{'foo ': bar}`) not being applied in Ivy. The issue comes from the fact that when the styling differ builds up the style map it uses the trimmed key to look up the value in the map that uses non-trimmed keys.

Fixes #34476.

PR Close #34539
2020-01-08 15:02:09 -08:00
crisbeto 6fda7f3da4 fix(ivy): warn instead of throwing for unknown elements (#34524)
Follow-up from [this discussion](https://github.com/angular/angular/pull/33419#discussion_r339296216). In Ivy we don't use the schema to validate tag names, but instead we use feature detection to figure out whether an element is supported. While this should generally be more accurate, it'll also end up throwing for some more innocent cases. E.g. now Ivy throws an error for `main` elements in IE which is accurate since IE doesn't support the element, but is annoying since there is no functionality attached.

These changes switch to logging a warning instead, similarly to what we're doing for unknown properties.

PR Close #34524
2020-01-08 15:01:42 -08:00
George Kalpakas 07ea6cf582 fix(ngcc): avoid error due to circular dependency in `EsmDependencyHost` (#34512)
Previously, there was circular dependency between `ngcc/src/utils.ts`,
`ngcc/src/dependencies/dependency_host.ts` and
`ngcc/src/dependencies/esm_dependency_host.ts`. More specifically,
`utils.ts` would [import from `esm_dependency_host.ts`][1], which would
[import from `dependency_host.ts`][2], which would in turn
[import from `utils.ts`][3].

This might be fine in some environments/module formats, but it can cause
unclear errors in the transpiled CommonJS/UMD format (given how Node.js
handles [cycles in module resolution][4]).
(An example error can be found [here][5].)

This commit fixes the problem by moving the code that depends on
`EsmDependencyHost` out of `utils.ts` and into a dedicated file under
`dependencies/`. It also converts the `createDtsDependencyHost()`
function to a class for consistency with the rest of the
`DependencyHost`s.

[1]: https://github.com/angular/angular/blob/18d89c9c8/packages/compiler-cli/ngcc/src/utils.ts#L10
[2]: https://github.com/angular/angular/blob/18d89c9c8/packages/compiler-cli/ngcc/src/dependencies/esm_dependency_host.ts#L10
[3]: https://github.com/angular/angular/blob/18d89c9c8/packages/compiler-cli/ngcc/src/dependencies/dependency_host.ts#L9
[4]: https://nodejs.org/api/modules.html#modules_cycles
[5]: https://circleci.com/gh/angular/angular/577581

PR Close #34512
2020-01-08 15:00:50 -08:00
George Kalpakas c38195f59e refactor(ngcc): use a special map for memoizing expensive-to-compute values (#34512)
Previously, in cases were values were expensive to compute and would be
used multiple times, a combination of a regular `Map` and a helper
function (`getOrDefault()`) was used to ensure values were only computed
once.

This commit uses a special `Map`-like structure to compute and memoize
such expensive values without the need to a helper function.

PR Close #34512
2020-01-08 15:00:50 -08:00
George Kalpakas 6606ce69f6 refactor(ngcc): avoid returning the same top-level helper calls multiple times (#34512)
This change should not have any impact on the code's behavior (based on
how the function is currently used), but it will avoid unnecessary work.

PR Close #34512
2020-01-08 15:00:50 -08:00
George Kalpakas 17d5e2bc99 refactor(ngcc): share code between `CommonJsReflectionHost` and `UmdReflectionHost` (#34512)
While different, CommonJS and UMD have a lot in common regarding the
their exports are constructed. Therefore, there was some code
duplication between `CommonJsReflectionHost` and `UmdReflectionHost`.

This commit extracts some of the common bits into a separate file as
helpers to allow reusing the code in both `ReflectionHost`s.

PR Close #34512
2020-01-08 15:00:49 -08:00
George Kalpakas d5fd742763 fix(ngcc): recognize re-exports with `require()` calls in UMD (#34512)
Previously, `UmdReflectionHost` would only recognize re-exports of the
form `__export(someIdentifier)` and not `__export(require('...'))`.
However, it is possible in some UMD variations to have the latter format
as well. See discussion in https://github.com/angular/angular/pull/34254/files#r359515373

This commit adds support for re-export of the form
`__export(require('...'))` in UMD.

PR Close #34512
2020-01-08 15:00:49 -08:00
George Kalpakas 6654f82522 fix(ngcc): correctly handle inline exports in UMD (#34512)
This fix was part of a broader `ngtsc`/`ngcc` fix in 02bab8cf9 (see
there for details). In 02bab8cf9, the fix was only applied to
`CommonJsReflectionHost`, but it is equally applicable to
`UmdReflectionHost`. Later in #34254, the fix was partially ported to
`UmdReflectionHost` by fixing the `extractUmdReexports()` method.

This commit fully fixes `ngcc`'s handling of inline exports for code in
UMD format.

PR Close #34512
2020-01-08 15:00:49 -08:00
7006 18d89c9c89 docs(forms): remove redundant word (#34584)
PR Close #34584
2020-01-07 10:59:51 -08:00
Andrew Scott 4d7a9db44c fix(ivy): Ensure ngProjectAs marker name appears at even attribute index (#34617)
The `getProjectAsAttrValue` in `node_selector_matcher` finds the
ProjectAs marker and then additionally checks that the marker appears in
an even index of the node attributes because "attribute names are stored
at even indexes". This is true for "regular" attribute bindings but
classes, styles, bindings, templates, and i18n do not necessarily follow
this rule because there can be an uneven number of them, causing the
next "special" attribute "name" to appear at an odd index. To address
this issue, ensure ngProjectAs is placed right after "regular"
attributes.

PR Close #34617
2020-01-07 10:51:46 -08:00
Troels Lenda 1b6ad15bc5 fix(common): remove trailing whitespace for CurrencyPipe (#34642)
Trimming any surrounding whitespace characters informatNumberToLocaleString
if currency symbol issupressed.

Closes #34641

PR Close #34642
2020-01-07 10:50:50 -08:00
George Kalpakas 10e29355db fix(ngcc): do not add trailing commas in UMD imports (#34545)
Previously, if `UmdRenderingFormatter#addImports()` was called with an
empty list of imports to add (i.e. no new imports were needed), it would
add trailing commas in several locations (arrays, function arguments,
function parameters), thus making the code imcompatible with legacy
browsers such as IE11.

This commit fixes it by ensuring that no trailing commas are added if
`addImports()` is called with an empty list of imports.
This is a follow-up to #34353.

Fixes #34525

PR Close #34545
2020-01-07 10:42:06 -08:00
Pete Bacon Darwin 4f42de9704 fix(ngcc): capture entry-point dependencies from typings as well as source (#34494)
ngcc computes a dependency graph of entry-points to ensure that
entry-points are processed in the correct order. Previously only the imports
in source files were analysed to determine the dependencies for each
entry-point.

This is not sufficient when an entry-point has a "type-only" dependency
 - for example only importing an interface from another entry-point.
In this case the "type-only" import does not appear in the
source code. It only appears in the typings files. This can cause a
dependency to be missed on the entry-point.

This commit fixes this by additionally processing the imports in the
typings program, as well as the source program.

Note that these missing dependencies could cause unexpected flakes when
running ngcc in async mode on multiple processes due to the way that
ngcc caches files when they are first read from disk.

Fixes #34411

// FW-1781

PR Close #34494
2020-01-07 10:35:03 -08:00
Pete Bacon Darwin 69950e3888 refactor(ngcc): resolve modules based on the provided `moduleResolver` (#34494)
The `DependencyHost` implementations were duplicating the "postfix" strings
which are used to find matching paths when resolving module specifiers.
Now the hosts reuse the postfixes given to the `ModuleResolver` that is
passed to the host.

PR Close #34494
2020-01-07 10:35:03 -08:00
Pete Bacon Darwin e2b184515b refactor(ngcc): pass dependency info to `collectDependencies()` (#34494)
Rather than return a new object of dependency info from calls to
`collectDependencies()` we now pass in an object that will be updated
with the dependency info. This is in preparation of a change where
we will collect dependency information from more than one
`DependencyHost`.

Also to better fit with this approach the name is changed from
`findDependencies()` to `collectDependencies()`.

PR Close #34494
2020-01-07 10:35:03 -08:00
Andrew Kushnir b4c5bdb093 fix(ivy): append `advance` instructions before `i18nExp` (#34436)
Prior to this commit, there were no `advance` instructions generated before `i18nExp` instructions and as a result, lifecycle hooks for components used inside i18n blocks were flushed too late. This commit adds the logic to generate `advance` instructions in front of `i18nExp` ones (similar to what we have in other places like interpolations, property bindings, etc), so that the necessary lifecycle hooks are flushed before expression value is captured.

PR Close #34436
2020-01-07 10:31:45 -08:00
skrikl 0254cba4b3 docs: Fix double 'as an' in description at line 2069 (#34373)
PR Close #34373
2020-01-07 10:29:41 -08:00
Andrew Kushnir effb92dfae fix(ivy): skip field inheritance if InheritDefinitionFeature is present on parent def (#34244)
The main logic of the `InheritDefinitionFeature` is to go through the prototype chain of a given Component and merge all Angular-specific information onto that Component def. The problem happens in case there is a Component in a hierarchy that also contains the `InheritDefinitionFeature` (i.e. it extends some other Component), so it inherits all Angular-specific information from its super class. As a result, the root Component may end up having duplicate information inherited from different Components in hierarchy.

Let's consider the following structure: `GrandChild` extends `Child` that extends `Base` and the `Base` class has a `HostListener`. In this scenario `GrandChild` and `Child` will have `InheritDefinitionFeature` included into the `features` list. The processing will happend in the following order:

- `Child` inherits `HostListener` from the `Base` class
- `GrandChild` inherits `HostListener` from the `Child` class
- since `Child` has a parent, `GrandChild` also inherits from the `Base` class

The result is that the `GrandChild` def has duplicated host listener, which is not correct.

This commit introduces additional logic that checks whether we came across a def that has `InheritDefinitionFeature` feature (which means that this def already inherited information from its super classes). If that's the case, we skip further fields-related inheritance logic, but keep going though the prototype chain to look for super classes that contain other features (like NgOnChanges), that we need to invoke for a given Component def.

PR Close #34244
2020-01-07 10:28:06 -08:00
crisbeto 5b864ede13 fix(ivy): TestBed not unwrapping imports array function when overriding provider (#34629)
Fixes an error that is thrown when a provider is overridden in `TestBed`, if the module definition of one of the imported modules uses a function for the `imports` that is set via `setNgModuleScope`. The problem was that we have a `for...of` loop that assumes that the imports are an array, but they can also be a function. This was handled correctly in other places, but this one was missed.

Note that the above-mentioned error is only thrown at runtime when the code is transpiled to es6. In es5 TS generates a call to a helper that handles the error silently so the attached unit test only fails in es6.

Fixes #34623.

PR Close #34629
2020-01-06 11:38:02 -08:00
ayazhafiz ee46b9b44f fix(language-service): correctly parse expressions in an attribute (#34517)
Currently, the language service provides completions in a template node
attribute by first checking if the attribute contains template bindings
to provide completions for, and then providing completions for the
expression in the attribute.

In the latter case, the expression AST was being constructed
"synthetically" inside the language service, in particular declaring the
expression to be a `PropertyRead` with an implicit receiver.
Unfortunately, this AST can be incorrect if the expression is actually a
property read on a component property receiver (e.g. when reading
`key` in the expression `obj.key`, `obj` is the receiver).

The fix is pretty simple - rather than a synthetic construction of the
AST, ask the expression parser to parse the expression in the attribute.

Fixes https://github.com/angular/vscode-ng-language-service/issues/523

PR Close #34517
2020-01-06 11:37:21 -08:00
Keen Yee Liau c079f38cbb feat(language-service): Show documentation on hover (#34506)
This commit adds dpcumentation to the hover tooltip.

PR closes https://github.com/angular/vscode-ng-language-service/issues/321

PR Close #34506
2020-01-06 11:36:57 -08:00
ivanwonder ba2fd31e62 fix(language-service): The pipe method should not include parentheses (#34485)
PR Close #34485
2020-01-06 11:31:14 -08:00
JoostK e116816131 refactor(ivy): let `strictTemplates` imply `fullTemplateTypeCheck` (#34195)
Previously, it was required that both `fullTemplateTypeCheck` and
`strictTemplates` had to be enabled for strict mode to be enabled. This
is strange, as `strictTemplates` implies `fullTemplateTypeCheck`. This
commit makes setting the `fullTemplateTypeCheck` flag optional so that
strict mode can be enabled by just setting `strictTemplates`.

PR Close #34195
2020-01-06 11:07:54 -08:00
JoostK 2e82357611 refactor(ivy): verify template type check options are compatible (#34195)
It is now an error if '"fullTemplateTypeCheck"' is disabled while
`"strictTemplates"` is enabled, as enabling the latter implies that the
former is also enabled.

PR Close #34195
2020-01-06 11:07:54 -08:00
JoostK 1de49ba369 refactor(ivy): consistently translate types to `ts.TypeNode` (#34021)
The compiler has a translation mechanism to convert from an Angular
`Type` to a `ts.TypeNode`, as appropriate. Prior to this change, it
would translate certain Angular expressions into their value equivalent
in TypeScript, instead of the correct type equivalent. This was possible
as the `ExpressionVisitor` interface is not strictly typed, with `any`s
being used for return values.

For example, a literal object was translated into a
`ts.ObjectLiteralExpression`, containing `ts.PropertyAssignment` nodes
as its entries. This has worked without issues as their printed
representation is identical, however it was incorrect from a semantic
point of view. Instead, a `ts.TypeLiteralNode` is created with
`ts.PropertySignature` as its members, which corresponds with the type
declaration of an object literal.

PR Close #34021
2020-01-06 11:06:07 -08:00
JoostK f27187c063 perf(ivy): support simple generic type constraints in local type ctors (#34021)
In Ivy's template type checker, type constructors are created for all
directive types to allow for accurate type inference to work. The type
checker has two strategies for dealing with such type constructors:

1. They can be emitted local to the type check block/type check file.
2. They can be emitted as static `ngTypeCtor` field into the directive
itself.

The first strategy is preferred, as it avoids having to update the
directive type which would cause a more expensive rebuild. However, this
strategy is not suitable for directives that have constrained generic
types, as those constraints would need to be present on the local type
constructor declaration. This is not trivial, as it requires that any
type references within a type parameter's constraint are imported into
the local context of the type check block.

For example, lets consider the `NgForOf` directive from '@angular/core'
looks as follows:

```typescript
import {NgIterable} from '@angular/core';

export class NgForOf<T, U extends NgIterable<T>> {}
```

The type constructor will then have the signature:
`(o: Pick<i1.NgForOf<T, U>, 'ngForOf'>) => i1.NgForOf<T, U>`

Notice how this refers to the type parameters `T` and `U`, so the type
constructor needs to be emitted into a scope where those types are
available, _and_ have the correct constraints.

Previously, the template type checker would detect the situation where a
type parameter is constrained, and would emit the type constructor
using strategy 2; within the directive type itself. This approach makes
any type references within the generic type constraints lexically
available:

```typescript
export class NgForOf<T, U extends NgIterable<T>> {
  static ngTypeCtor<T = any, U extends NgIterable<T> = any>
    (o: Pick<NgForOf<T, U>, 'ngForOf'>): NgForOf<T, U> { return null!; }
}
```

This commit introduces the ability to emit a type parameter with
constraints into a different context, under the condition that it can
be imported from an absolute module. This allows a generic type
constructor to be emitted into a type check block or type check file
according to strategy 1, as imports have been generated for all type
references within generic type constraints. For example:

```typescript
import * as i0 from '@angular/core';
import * as i1 from '@angular/common';

const _ctor1: <T = any, U extends i0.NgIterable<T> = any>
  (o: Pick<i1.NgForOf<T, U>, 'ngForOf'>) => i1.NgForOf<T, U> = null!;
```

Notice how the generic type constraint of `U` has resulted in an import
of `@angular/core`, and the `NgIterable` is transformed into a qualified
name during the emitting process.

Resolves FW-1739

PR Close #34021
2020-01-06 11:06:07 -08:00