When TypeScript downlevels ES2015+ code to ES5, it uses some helper
functions to emulate some ES2015+ features, such as spread syntax. The
TypeScript compiler can be configured to emit these helpers into the
transpiled code (which is controlled by the `noEmitHelpers` option -
false by default). It can also be configured to import these helpers
from the `tslib` module (which is controlled by the `importHelpers`
option - false by default).
While most of the time the helpers will be either emitted or imported,
it is possible that one configures their app to neither emit nor import
them. In that case, the helpers could, for example, be made available on
the global object. This is what `@nativescript/angular`
v9.0.0-next-2019-11-12-155500-01 does. See, for example, [common.js][1].
Ngcc must be able to detect and statically evaluate these helpers.
Previously, it was only able to detect emitted or imported helpers.
This commit adds support for detecting these helpers if they are neither
emitted nor imported. It does this by checking identifiers for which no
declaration (either concrete or inline) can be found against a list of
known TypeScript helper function names.
[1]: https://unpkg.com/browse/@nativescript/angular@9.0.0-next-2019-11-12-155500-01/common.js
PR Close#36418
In #36089, `DelegatingReflectionHost` was introduced. Under the hood, it
delegates another `NgccReflectionHost` in order to reflect over the
program's source files, while using a different TypeScript
`ReflectionHost` to reflect over `.d.ts` files (which is how external
dependencies are represented in the program).
Previously, the `NgccReflectionHost`s were used directly in tests. This
does not exercise them in the way they are exercised in the actual
program, because (when used directly) they will also reflect on `.d.ts`
files too (instead of delegating to the TypeScript `ReflectionHost`).
This could hide bugs that would happen on the actual program.
This commit fixes this by using the `DelegatingReflectionHost` in the
various `NgccReflectionHost` tests.
NOTE:
This change will cause some of the existing tests to start failing.
These failures demonstrate pre-existing bugs in ngcc, that were hidden
due to the tests' being inconsistent with how the `ReflectionHost`s are
used in the actual program. They will be fixed in the next commit.
PR Close#36284
When ngcc is compiling an entry-point, it uses a `ReflectionHost` that
is specific to its format, e.g. ES2015, ES5, UMD or CommonJS. During the
compilation of that entry-point however, the reflector may be used to
reflect into external libraries using their declaration files.
Up until now this was achieved by letting all `ReflectionHost` classes
consider their parent class for reflector queries, thereby ending up in
the `TypeScriptReflectionHost` that is a common base class for all
reflector hosts. This approach has proven to be prone to bugs, as
failing to call into the base class would cause incompatibilities with
reading from declaration files.
The observation can be made that there's only two distinct kinds of
reflection host queries:
1. the reflector query is about code that is part of the entry-point
that is being compiled, or
2. the reflector query is for an external library that the entry-point
depends on, in which case the information is reflected
from the declaration files.
The `ReflectionHost` that was chosen for the entry-point should serve
only reflector queries for the first case, whereas a regular
`TypeScriptReflectionHost` should be used for the second case. This
avoids the problem where a format-specific `ReflectionHost` fails to
handle the second case correctly, as it isn't even considered for such
reflector queries.
This commit introduces a `ReflectionHost` that delegates to the
`TypeScriptReflectionHost` for AST nodes within declaration files,
otherwise delegating to the format-specific `ReflectionHost`.
Fixes#35078
Resolves FW-1859
PR Close#36089
This commit adds support in the Angular monorepo and in the Angular
compiler(s) for TypeScript 3.8. All packages can now compile with
TS 3.8.
For most of the repo, only a handful few typings adjustments were needed:
* TS 3.8 has a new `CustomElementConstructor` DOM type, which enforces a
zero-argument constructor. The `NgElementConstructor` type previously
declared a required `injector` argument despite the fact that its
implementation allowed `injector` to be optional. The interface type was
updated to reflect the optionality of the argument.
* Certain error messages were changed, and expectations in tests were
updated as a result.
* tsserver (part of language server) now returns performance information in
responses, so test expectations were changed to only assert on the actual
body content of responses.
For compiler-cli and schematics (which use the TypeScript AST) a major
breaking change was the introduction of the export form:
```typescript
export * as foo from 'bar';
```
This is a `ts.NamespaceExport`, and the `exportClause` of a
`ts.ExportDeclaration` can now take this type as well as `ts.NamedExports`.
This broke a lot of places where `exportClause` was assumed to be
`ts.NamedExports`.
For the most part these breakages were in cases where it is not necessary
to handle the new `ts.NamedExports` anyway. ngtsc's design uses the
`ts.TypeChecker` APIs to understand syntax and so automatically supports the
new form of exports.
The View Engine compiler on the other hand extracts TS structures into
metadata.json files, and that format was not designed for namespaced
exports. As a result it will take a nontrivial amount of work if we want to
support such exports in View Engine. For now, these new exports are not
accounted for in metadata.json, and so using them in "folded" Angular
expressions will result in errors (probably claiming that the referenced
exported namespace doesn't exist).
Care was taken to only use TS APIs which are present in 3.7/3.6, as Angular
needs to remain compatible with these for the time being.
This commit does not update angular.io.
PR Close#35864
In ES5 code, TypeScript requires certain helpers (such as
`__spreadArrays()`) to be able to support ES2015+ features. These
helpers can be either imported from `tslib` (by setting the
`importHelpers` TS compiler option to `true`) or emitted inline (by
setting the `importHelpers` and `noEmitHelpers` TS compiler options to
`false`, which is the default value for both).
Ngtsc's `StaticInterpreter` (which is also used during ngcc processing)
is able to statically evaluate some of these helpers (currently
`__assign()`, `__spread()` and `__spreadArrays()`), as long as
`ReflectionHost#getDefinitionOfFunction()` correctly detects the
declaration of the helper. For this to happen, the left-hand side of the
corresponding call expression (i.e. `__spread(...)` or
`tslib.__spread(...)`) must be evaluated as a function declaration for
`getDefinitionOfFunction()` to be called with.
In the case of imported helpers, the `tslib.__someHelper` expression was
resolved to a function declaration of the form
`export declare function __someHelper(...args: any[][]): any[];`, which
allows `getDefinitionOfFunction()` to correctly map it to a TS helper.
In contrast, in the case of emitted helpers (and regardless of the
module format: `CommonJS`, `ESNext`, `UMD`, etc.)), the `__someHelper`
identifier was resolved to a variable declaration of the form
`var __someHelper = (this && this.__someHelper) || function () { ... }`,
which upon further evaluation was categorized as a `DynamicValue`
(prohibiting further evaluation by the `getDefinitionOfFunction()`).
As a result of the above, emitted TypeScript helpers were not evaluated
in ES5 code.
---
This commit changes the detection of TS helpers to leverage the existing
`KnownFn` feature (previously only used for built-in functions).
`Esm5ReflectionHost` is changed to always return `KnownDeclaration`s for
TS helpers, both imported (`getExportsOfModule()`) as well as emitted
(`getDeclarationOfIdentifier()`).
Similar changes are made to `CommonJsReflectionHost` and
`UmdReflectionHost`.
The `KnownDeclaration`s are then mapped to `KnownFn`s in
`StaticInterpreter`, allowing it to statically evaluate call expressions
involving any kind of TS helpers.
Jira issue: https://angular-team.atlassian.net/browse/FW-1689
PR Close#35191
When statically evaluating CommonJS code it is possible to find that we
are looking for the declaration of an identifier that actually came from
a typings file (rather than a CommonJS file).
Previously, the CommonJS reflection host would always try to use a
CommonJS specific algorithm for finding identifier declarations, but
when the id is actually in a typings file this resulted in the returned
declaration being the containing file of the declaration rather than the
declaration itself.
Now the CommonJS reflection host will check to see if the file
containing the identifier is a typings file and use the appropriate
stategy.
(Note: This is the equivalent of #34356 but for CommonJS.)
PR Close#35191
In ES5 and ES2015, class identifiers may have aliases. Previously, the
`NgccReflectionHost`s recognized the following formats:
- ES5:
```js
var MyClass = (function () {
function InnerClass() {}
InnerClass_1 = InnerClass;
...
}());
```
- ES2015:
```js
let MyClass = MyClass_1 = class MyClass { ... };
```
In addition to the above, this commit adds support for recognizing an
alias outside the IIFE in ES5 classes (which was previously not
supported):
```js
var MyClass = MyClass_1 = (function () { ... }());
```
Jira issue: [FW-1869](https://angular-team.atlassian.net/browse/FW-1869)
Partially addresses #35399.
PR Close#35527
Previously, while trying to build an `NgccReflectionHost`'s
`privateDtsDeclarationMap`, `computePrivateDtsDeclarationMap()` would
try to collect exported declarations from all source files of the
program (i.e. without checking whether they were within the target
package, as happens for declarations in `.d.ts` files).
Most of the time, that would not be a problem, because external packages
would be represented as `.d.ts` files in the program. But when an
external package had no typings, the JS files would be used instead. As
a result, the `ReflectionHost` would try to (unnecessarilly) parse the
file in order to extract exported declarations, which in turn would be
harmless in most cases.
There are certain cases, though, where the `ReflectionHost` would throw
an error, because it cannot parse the external package's JS file. This
could happen, for example, in `UmdReflectionHost`, which expects the
file to contain exactly one statement. See #34544 for more details on a
real-world failure.
This commit fixes the issue by ensuring that
`computePrivateDtsDeclarationMap()` will only collect exported
declarations from files within the target package.
Jira issue: [FW-1794](https://angular-team.atlassian.net/browse/FW-1794)
Fixes#34544
PR Close#34811
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
The naïve matching algorithm we previously used to match declarations in
source files to declarations in typings files was based only on the name
of the thing being declared. This did not handle cases where the declared
item had been exported via an alias - a common scenario when one of the two
file sets (source or typings) has been flattened, while the other has not.
The new algorithm tries to overcome this by creating two maps of export
name to declaration (i.e. `Map<string, ts.Declaration>`).
One for the source files and one for the typings files.
It then joins these two together by matching export names, resulting in a
new map that maps source declarations to typings declarations directly
(i.e. `Map<ts.Declaration, ts.Declaration>`).
This new map can handle the declaration names being different between the
source and typings as long as they are ultimately both exported with the
same alias name.
Further more, there is one map for "public exports", i.e. exported via the
root of the source tree (the entry-point), and another map for "private
exports", which are exported from individual files in the source tree but
not necessarily from the root. This second map can be used to "guess"
the mapping between exports in a deep (non-flat) file tree, which can be
used by ngcc to add required private exports to the entry-point.
Fixes#33593
PR Close#34254
In TS we can re-export imports using statements of the form:
```
export * from 'some-import';
```
This can be downleveled in CommonJS to either:
```
__export(require('some-import'));
```
or
```
var someImport = require('some-import');
__export(someImport);
```
Previously we only supported the first downleveled version.
This commit adds support for the second version.
PR Close#34254
Previously individual properties of the src bundle program were
passed to the reflection host constructors. But going forward,
more properties will be required. To prevent the signature getting
continually larger and more unwieldy, this change just passes the
whole src bundle to the constructor, allowing it to extract what it
needs.
PR Close#34254
The reflection hosts have been updated to support the following
code forms, which were found in some minified library code:
* The class IIFE not being wrapped in parentheses.
* Calls to `__decorate()` being combined with the IIFE return statement.
PR Close#33777
In ES5 the class consists of an outer variable declaration that is
initialised by an IIFE. Inside the IIFE the class is implemented by
an inner function declaration that is returned from the IIFE.
This inner declaration may have a different name to the outer
declaration.
This commit overrides `getInternalNameOfClass()` and
`getAdjacentNameOfClass()` in `Esm5ReflectionHost` with methods that
can find the correct inner declaration name identifier.
PR Close#33533
In the ReflectionHost API, a 'viaModule' indicates that a particular value
originated in another absolute module. It should always be 'null' for values
originating in relatively-imported modules.
This commit fixes a bug in the CommonJsReflectionHost where viaModule would
be reported even for relatively-imported values, which causes invalid import
statements to be generated during compilation.
A test is added to verify the correct behavior.
FW-1628 #resolve
PR Close#33192
In ngcc's reflection host for UMD and CommonJS bundles, custom logic is
present to resolve import details of an identifier. However, this custom
logic is unable to resolve an import for an identifier inside of
declaration files, as such files use the regular ESM import syntax.
As a consequence of this limitation, ngtsc is unable to resolve
`ModuleWithProviders` imports that are declared in an external library.
In that situation, ngtsc determines the type of the actual `NgModule`
that is imported, by looking in the library's declaration files for the
generic type argument on `ModuleWithProviders`. In this process, ngtsc
resolves the import for the `ModuleWithProviders` identifier to verify
that it is indeed the `ModuleWithProviders` type from `@angular/core`.
So, when the UMD reflection host was in use this resolution would fail,
therefore no `NgModule` type could be detected.
This commit fixes the bug by using the regular import resolution logic
in addition to the custom resolution logic that is required for UMD
and CommonJS bundles.
Fixes#31791
PR Close#32619
In ngcc's reflection hosts for compiled JS bundles, such as ESM2015,
special care needs to be taken for classes as there may be an outer
declaration (referred to as "declaration") and an inner declaration
(referred to as "implementation") for a given class. Therefore, there
will also be two `ts.Symbol`s bound per class, and ngcc needs to switch
between those declarations and symbols depending on where certain
information can be found.
Prior to this commit, the `NgccReflectionHost` interface had methods
`getClassSymbol` and `findClassSymbols` that would return a `ts.Symbol`.
These class symbols would be used to kick off compilation of components
using ngtsc, so it is important for these symbols to correspond with the
publicly visible outer declaration of the class. However, the ESM2015
reflection host used to return the `ts.Symbol` for the inner
declaration, if the class was declared as follows:
```javascript
var MyClass = class MyClass {};
```
For the above code, `Esm2015ReflectionHost.getClassSymbol` would return
the `ts.Symbol` corresponding with the `class MyClass {}` declaration,
whereas it should have corresponded with the `var MyClass` declaration.
As a consequence, no `NgModule` could be resolved for the component, so
no components/directives would be in scope for the component. This
resulted in errors during runtime.
This commit resolves the issue by introducing a `NgccClassSymbol` that
contains references to both the outer and inner `ts.Symbol`, instead of
just a single `ts.Symbol`. This avoids the unclarity of whether a
`ts.Symbol` corresponds with the outer or inner declaration.
More details can be found here: https://hackmd.io/7nkgWOFWQlSRAuIW_8KPPwFixes#32078
Closes FW-1507
PR Close#32539
ngcc needs to solve a unique problem when compiling typings for an
entrypoint: it must resolve a declaration within a .js file to its
representation in a .d.ts file. Since such .d.ts files can be used in deep
imports without ever being referenced from the "root" .d.ts, it's not enough
to simply match exported types to the root .d.ts. ngcc must build an index
of all .d.ts files.
Previously, this operation had a bug: it scanned all .d.ts files in the
.d.ts program, not only those within the package. Thus, if a class in the
program happened to share a name with a class exported from a dependency's
.d.ts, ngcc might accidentally modify the wrong .d.ts file, causing a
variety of issues downstream.
To fix this issue, ngcc's .d.ts scanner now limits the .d.ts files it
indexes to only those declared in the current package.
PR Close#32129
One of the compiler's tasks is to enumerate the exports of a given ES
module. This can happen for example to resolve `foo.bar` where `foo` is a
namespace import:
```typescript
import * as foo from './foo';
@NgModule({
directives: [foo.DIRECTIVES],
})
```
In this case, the compiler must enumerate the exports of `foo.ts` in order
to evaluate the expression `foo.DIRECTIVES`.
When this operation occurs under ngcc, it must deal with the different
module formats and types of exports that occur. In commonjs code, a problem
arises when certain exports are downleveled.
```typescript
export const DIRECTIVES = [
FooDir,
BarDir,
];
```
can be downleveled to:
```javascript
exports.DIRECTIVES = [
FooDir,
BarDir,
```
Previously, ngtsc and ngcc expected that any export would have an associated
`ts.Declaration` node. `export class`, `export function`, etc. all retain
`ts.Declaration`s even when downleveled. But the `export const` construct
above does not. Therefore, ngcc would not detect `DIRECTIVES` as an export
of `foo.ts`, and the evaluation of `foo.DIRECTIVES` would therefore fail.
To solve this problem, the core concept of an exported `Declaration`
according to the `ReflectionHost` API is split into a `ConcreteDeclaration`
which has a `ts.Declaration`, and an `InlineDeclaration` which instead has
a `ts.Expression`. Differentiating between these allows ngcc to return an
`InlineDeclaration` for `DIRECTIVES` and correctly keep track of this
export.
PR Close#32129
Any decorator information present in TypeScript is emitted into the
generated JavaScript sources by means of `__decorate` call. This call
contains both the decorators as they existed in the original source
code, together with calls to `tslib` helpers that convey additional
information on e.g. type information and parameter decorators. These
different kinds of decorator calls were not previously distinguished on
their own, but instead all treated as `Decorator` by themselves. The
"decorators" that were actually `tslib` helper calls were conveniently
filtered out because they were not imported from `@angular/core`, a
characteristic that ngcc uses to drop certain decorators.
Note that this posed an inconsistency in ngcc when it processes
`@angular/core`'s UMD bundle, as the `tslib` helper functions have been
inlined in said bundle. Because of the inlining, the `tslib` helpers
appear to be from `@angular/core`, so ngcc would fail to drop those
apparent "decorators". This inconsistency does not currently cause any
issues, as ngtsc is specifically looking for decorators based on their
name and any remaining decorators are simply ignored.
This commit rewrites the decorator analysis of a class to occur all in a
single phase, instead of all throughout the `ReflectionHost`. This
allows to categorize the various decorate calls in a single sweep,
instead of constantly needing to filter out undesired decorate calls on
the go. As an added benefit, the computed decorator information is now
cached per class, such that subsequent reflection queries that need
decorator information can reuse the cached info.
PR Close#31614
Previously we expected the constructor parameter `decorators`
property to be an array wrapped in a function. Now we also support
an array not wrapped in a function.
PR Close#30591
To improve cross platform support, all file access (and path manipulation)
is now done through a well known interface (`FileSystem`).
For testing a number of `MockFileSystem` implementations are provided.
These provide an in-memory file-system which emulates operating systems
like OS/X, Unix and Windows.
The current file system is always available via the static method,
`FileSystem.getFileSystem()`. This is also used by a number of static
methods on `AbsoluteFsPath` and `PathSegment`, to avoid having to pass
`FileSystem` objects around all the time. The result of this is that one
must be careful to ensure that the file-system has been initialized before
using any of these static methods. To prevent this happening accidentally
the current file system always starts out as an instance of `InvalidFileSystem`,
which will throw an error if any of its methods are called.
You can set the current file-system by calling `FileSystem.setFileSystem()`.
During testing you can call the helper function `initMockFileSystem(os)`
which takes a string name of the OS to emulate, and will also monkey-patch
aspects of the TypeScript library to ensure that TS is also using the
current file-system.
Finally there is the `NgtscCompilerHost` to be used for any TypeScript
compilation, which uses a given file-system.
All tests that interact with the file-system should be tested against each
of the mock file-systems. A series of helpers have been provided to support
such tests:
* `runInEachFileSystem()` - wrap your tests in this helper to run all the
wrapped tests in each of the mock file-systems.
* `addTestFilesToFileSystem()` - use this to add files and their contents
to the mock file system for testing.
* `loadTestFilesFromDisk()` - use this to load a mirror image of files on
disk into the in-memory mock file-system.
* `loadFakeCore()` - use this to load a fake version of `@angular/core`
into the mock file-system.
All ngcc and ngtsc source and tests now use this virtual file-system setup.
PR Close#30921
Packages that have been compiled using an older version of TypeScript
can have their decorators at the top-level of the ES5 bundles, instead
of inside the IIFE that is emitted for the class. Before this change,
ngcc only took static property assignments inside the IIFE into account,
therefore missing the decorators that were assigned at the top-level.
This commit extends the ES5 host to look for static properties in two
places. Testcases for all bundle formats that contain ES5 have been added
to ensure that this works in the various flavours.
A patch is included to support UMD bundles. The UMD factory affects how
TypeScripts binds the static properties to symbols, see the docblock of
the patch function for more details.
PR Close#30795
9d9c9e43e5 has been created a few days ago
and wasn't rebased on top of recent changes that introduces a commonjs host.
This means that tests for the commonjs host haven't been updated to work with
the changes from from #30492 and now fail in `master`.
PR Close#30967
Currently undecorated classes are intentionally not processed
with ngcc. This is causing unexpected behavior because decorator
handlers such as `base_def.ts` are specifically interested in class
definitions without top-level decorators, so that the base definition
can be generated if there are Angular-specific class members.
In order to ensure that undecorated base-classes work as expected
with Ivy, we need to run the decorator handlers for all top-level
class declarations (not only for those with decorators). This is similar
to when `ngtsc` runs decorator handlers when analyzing source-files.
Resolves FW-1355. Fixes https://github.com/angular/components/issues/16178
PR Close#30821
George Kalpakas
JoostK
Alex Rickabaugh
Pete Bacon Darwin
Paul Gschwendtner