This fixes an issue with commit b6f6b117. In this commit, default imports
processed in a type-to-value conversion were recorded as non-local imports
with a '*' name, and the ImportManager generated a new default import for
them. When transpiled to ES2015 modules, this resulted in the following
correct code:
import i3 from './module';
// somewhere in the file, a value reference of i3:
{type: i3}
However, when the AST with this synthetic import and reference was
transpiled to non-ES2015 modules (for example, to commonjs) an issue
appeared:
var module_1 = require('./module');
{type: i3}
TypeScript renames the imported identifier from i3 to module_1, but doesn't
substitute later references to i3. This is because the import and reference
are both synthetic, and never went through the TypeScript AST step of
"binding" which associates the reference to its import. This association is
important during emit when the identifiers might change.
Synthetic (transformer-added) imports will never be bound properly. The only
possible solution is to reuse the user's original import and the identifier
from it, which will be properly downleveled. The issue with this approach
(which prompted the fix in b6f6b117) is that if the import is only used in a
type position, TypeScript will mark it for deletion in the generated JS,
even though additional non-type usages are added in the transformer. This
again would leave a dangling import.
To work around this, it's necessary for the compiler to keep track of
identifiers that it emits which came from default imports, and tell TS not
to remove those imports during transpilation. A `DefaultImportTracker` class
is implemented to perform this tracking. It implements a
`DefaultImportRecorder` interface, which is used to record two significant
pieces of information:
* when a WrappedNodeExpr is generated which refers to a default imported
value, the ts.Identifier is associated to the ts.ImportDeclaration via
the recorder.
* when that WrappedNodeExpr is later emitted as part of the statement /
expression translators, the fact that the ts.Identifier was used is
also recorded.
Combined, this tracking gives the `DefaultImportTracker` enough information
to implement another TS transformer, which can recognize default imports
which were used in the output of the Ivy transform and can prevent them
from being elided. This is done by creating a new ts.ImportDeclaration for
the imports with the same ts.ImportClause. A test verifies that this works.
PR Close#29266
Sometimes declarations are not exported publicly but are exported under
a private name. In this case, rather than adding a completely new
export to the entry point, we should create an export that aliases the
private name back to the original public name.
This is important when the typings files have been rolled-up using a tool
such as the [API Extractor](https://api-extractor.com/). In this case
the internal type of an aliased private export will be removed completely
from the typings file, so there is no "original" type to re-export.
For example:
If there are the following TS files:
**entry-point.ts**
```ts
export {Internal as External} from './internal';
```
**internal.ts**
```ts
export class Internal {
foo(): void;
}
```
Then the API Extractor might roll up the .d.ts files into:
```ts
export declare class External {
foo(): void;
}
```
In this case ngcc should add an export so the file looks like:
```ts
export declare class External {
foo(): void;
}
export {External as Internal};
```
PR Close#28735
This commit refactors and expands ngtsc's support for generating imports of
values from imports of types (this is used for example when importing a
class referenced in a type annotation in a constructor).
Previously, this logic handled "import {Foo} from" and "import * as foo
from" style imports, but failed on imports of default values ("import
Foo from"). This commit moves the type-to-value logic to a separate file and
expands it to cover the default import case. Doing this also required
augmenting the ImportManager to track default as well as non-default import
generation. The APIs were made a little cleaner at the same time.
PR Close#29146
The ultimate goal of this commit is to make use of fileNameToModuleName to
get the module specifier to use when generating an import, when that API is
available in the CompilerHost that ngtsc is created with.
As part of getting there, the way in which ngtsc tracks references and
generates import module specifiers is refactored considerably. References
are tracked with the Reference class, and previously ngtsc had several
different kinds of Reference. An AbsoluteReference represented a declaration
which needed to be imported via an absolute module specifier tracked in the
AbsoluteReference, and a RelativeReference represented a declaration from
the local program, imported via relative path or referred to directly by
identifier if possible. Thus, how to refer to a particular declaration was
encoded into the Reference type _at the time of creation of the Reference_.
This commit refactors that logic and reduces Reference to a single class
with no subclasses. A Reference represents a node being referenced, plus
context about how the node was located. This context includes a
"bestGuessOwningModule", the compiler's best guess at which absolute
module specifier has defined this reference. For example, if the compiler
arrives at the declaration of CommonModule via an import to @angular/common,
then any references obtained from CommonModule (e.g. NgIf) will also be
considered to be owned by @angular/common.
A ReferenceEmitter class and accompanying ReferenceEmitStrategy interface
are introduced. To produce an Expression referring to a given Reference'd
node, the ReferenceEmitter consults a sequence of ReferenceEmitStrategy
implementations.
Several different strategies are defined:
- LocalIdentifierStrategy: use local ts.Identifiers if available.
- AbsoluteModuleStrategy: if the Reference has a bestGuessOwningModule,
import the node via an absolute import from that module specifier.
- LogicalProjectStrategy: if the Reference is in the logical project
(is under the project rootDirs), import the node via a relative import.
- FileToModuleStrategy: use a FileToModuleHost to generate the module
specifier by which to import the node.
Depending on the availability of fileNameToModuleName in the CompilerHost,
then, a different collection of these strategies is used for compilation.
PR Close#28523
Upcoming work to implement import resolution will change the dependencies
of some higher-level classes in ngtsc & ngcc. This necessitates changes in
how these classes are created and the lifecycle of the ts.Program in ngtsc
& ngcc.
To avoid complicating the implementation work with refactoring as a result
of the new dependencies, the refactoring is performed in this commit as a
separate prepatory step.
In ngtsc, the testing harness is modified to allow easier access to some
aspects of the ts.Program.
In ngcc, the main change is that the DecorationAnalyzer is created with the
ts.Program as a constructor parameter. This is not a lifecycle change, as
it was previously created with the ts.TypeChecker which is derived from the
ts.Program anyways. This change requires some reorganization in ngcc to
accommodate, especially in testing harnesses where DecorationAnalyzer is
created manually in a number of specs.
PR Close#27743
A surprising interaction with the MagicString library caused inserted
Ivy definitions to be dropped during the removal of decorators, iff all
decorators on the class could be removed. In that case, the removal
location corresponds with the exact location where Ivy definitions were
inserted into.
This commit moves the removal of decorators to occur before Ivy
definitions are inserted. This effectively avoids the problem, as later
inserted text fragments will be retained by MagicString.
PR Close#27159
Ngcc will now render additional exports for classes that are referenced in
`NgModule` decorated classes, but which were not publicly exported
from an entry-point of the package.
This is important because when ngtsc compiles libraries processed by ngcc
it needs to be able to publcly access decorated classes that are referenced
by `NgModule` decorated classes in order to build templates that use these
classes.
Doing this re-exporting is not without its risks. There are chances that
the class is not exported correctly: there may already be similarly named
exports from the entry-point or the class may be being aliased. But there
is not much more we can do from the point of view of ngcc to workaround
such scenarios. Generally, packages should have been built so that this
approach works.
PR Close#26906
There are a number of variables that need to be passed around
the program, in particular to the renderers, which benefit from being
stored in well defined objects.
The new `EntryPointBundle` structure is a specific format of an entry-point
and contains the compiled `BundleProgram` objects for the source and typings,
if appropriate.
This change helps with future refactoring, where we may need to add new
properties to this object. It allows us to maintain more stable APIs between
the constituent parts of ngcc, rather than passing lots of primitive values
around throughout the program.
PR Close#26906
Previously the ivy definition calls we going directly after the
class constructor function But this meant that the lifecycle
hooks attached to the prototype were ignored by the ngtsc
compiler.
Now the definitions are written to the end of the IIFE block,
just before the return statement.
Closes#26849
PR Close#26856
For each package entry-point there is only one format that
is used to compile the typings files (.d.ts). This will be
either esm2015 or fesm2015 (preferred). So we would not run
any dts processing in the renderer if we are not compiling
the appropriate format.
PR Close#26403
1) The `DecorationAnalyzer now analyzes all source files, rather than just
the entry-point files, which fixes#26183.
2) The `DecoratorAnalyzer` now runs all the `handler.analyze()` calls
across the whole entry-point *before* running `handler.compile()`. This
ensures that dependencies between the decorated classes *within* an
entry-point are known to the handlers when running the compile process.
3) The `Renderer` now does the transformation of the typings (.d.ts) files
which allows us to support packages that only have flat format
entry-points better, and is faster, since we won't parse `.d.ts` files twice.
PR Close#26403
The rendering of typings is not specific to the package
format, so it doesn't make sense to put it in a specific
renderer.
As a result there is no real difference between esm5 and esm2015
renderers, so there is no point in having separate classes.
PR Close#26403
Originally, the ivy_switch mechanism used Bazel genrules to conditionally
compile one TS file or another depending on whether ngc or ngtsc was the
selected compiler. This was done because we wanted to avoid importing
certain modules (and thus pulling them into the build) if Ivy was on or
off. This mechanism had a major drawback: ivy_switch became a bottleneck
in the import graph, as it both imports from many places in the codebase
and is imported by many modules in the codebase. This frequently resulted
in cyclic imports which caused issues both with TS and Closure compilation.
It turns out ngcc needs both code paths in the bundle to perform the switch
during its operation anyway, so import switching was later abandoned. This
means that there's no real reason why the ivy_switch mechanism needed to
operate at the Bazel level, and for the ivy_switch file to be a bottleneck.
This commit removes the Bazel-level ivy_switch mechanism, and introduces
an additional TypeScript transform in ngtsc (and the pass-through tsc
compiler used for testing JIT) to perform the same operation that ngcc
does, and flip the switch during ngtsc compilation. This allows the
ivy_switch file to be removed, and the individual switches to be located
directly next to their consumers in the codebase, greatly mitigating the
circular import issues and making the mechanism much easier to use.
As part of this commit, the tag for marking switched variables was changed
from __PRE_NGCC__ to __PRE_R3__, since it's no longer just ngcc which
flips these tags. Most variables were renamed from R3_* to SWITCH_* as well,
since they're referenced mostly in render2 code.
Test strategy: existing test coverage is more than sufficient - if this
didn't work correctly it would break the hello world and todo apps.
PR Close#26550
Previously we only removed assignments to `Class.decorators = [];`
if the array was not empty.
Now we also remove calls to `__decorate([])`, similarly.
PR Close#26236
Closure compiler requires that the i18n message constants of the form
const MSG_XYZ = goog.getMessage('...');
have names that are unique across an entire compilation, even if the
variables themselves are local to a given module. This means that in
practice these names must be unique in a codebase.
The best way to guarantee this requirement is met is to encode the
relative file name of the file into which the constant is being written
into the constant name itself. This commit implements that solution.
PR Close#25689
Alex Rickabaugh
Alan Agius
JoostK
Pete Bacon Darwin