…ld (#45024)

When `@angular/compiler` processes metadata and compiles a definition field,
it might also choose to return statements that are associated with that
definition, and should be included after the type being compiled. Currently,
the linker ignores these statements, as there are none generated that are
relevant in the linking operation.

A challenge to supporting such associated statements is that the linker
operates on "declare" expressions, and replaces those expressions with other
expressions. It does not have the capability to append statements after the
whole type. The linker actually faces this challenge with statements from
the `ConstantPool` as well, and solves this problem by generating an IIFE
expression that executes the statements and then returns the definition
expression.

Previously, an `EmitScope` processed the definition and converted it to an
expression, as well as collected constant statements from a `ConstantPool`.
A special `IifeEmitScope` implementation was used when emitting into a
context where top-level constant statements couldn't be added at all, and
uses the IIFE strategy in this case.

This commit adds blanket support for associated statements to the linker
using this IIFE strategy. The main `EmitScope` now uses the IIFE strategy to
emit associated statements, and `IifeEmitScope` has been renamed to
`LocalEmitScope`. Now, the `LocalEmitScope` represents constant statements
as associated statements to the main `EmitScope` implementation, so they
get included in the IIFE as well.

Tests are adjusted/added to cover this new behavior. This is a refactoring
commit because no live generated code is affected - there are no cases where
associated statements are present in linked definitions today.

PR Close #45024

… ids (#45024)

Angular contains an NgModule registry, which allows a user to declare
NgModules with string ids and retrieve them via those ids, using the
`getNgModuleById` API.

Previously, we attempted to structure this registration in a clever fashion
to allow for tree-shaking of registered NgModules (that is, those with ids).
This sort of worked due to the accidental alignment of behaviors from the
different tree-shakers involved. However, this trick relies on the
generation of `.ngfactory` files and how they're specifically processed in
various bundling scenarios. We intend to remove `.ngfactory` files, hence
we can no longer rely on them in this way.

The correct solution here is to recognize that `@NgModule({id})` is
inherently declaring a global side-effect, and such classes should not
really be eligible for tree-shaking in the first place. This commit removes
all the old registration machinery, and standardizes on generating a side-
effectful call to `registerNgModuleType` for NgModules that have ids.

There is some risk here that NgModules with unnecessary `id`s may not
tree-shake as a result of this change, whereas they would have in previous
circumstances. The fix here should be to remove the `id` if it's not needed.
Specifying an `id` is a request that the NgModule be retained regardless of
any other references, in case it is later looked up by string id.

PR Close #45024

…5024)

Previously, the `TraitCompiler` would naively consider a compilation as
failed if either analysis or resolution produced any diagnostics. This
commit adjusts the logic to only consider error diagnostics, which allows
warnings to be produced from `DecoratorHandler`s.

This is a precursor commit to introducing such a warning. As such, the
logic here will be tested in the next commit.

PR Close #45024

#45024)

In early versions of Angular, it was sometimes necessary to provide a
`moduleId` to `@Component` metadata, and the common pattern for doing this
was to set `moduleId: module.id`. This relied on the bundler to fill in a
value for `module.id`.

However, due to the superficial similarity between `Component.moduleId` and
`NgModule.id`, many users ended up setting `id: module.id` in their
NgModules. This is an anti-pattern that has a few negative effects,
including preventing the NgModule from tree-shaking properly.

This commit changes the compiler to ignore `id: module.id` in NgModules, and
instead provide a warning which suggests removing the line entirely.

PR Close #45024

…r#45024)

The `compileNgModule` operation previously supported a flag `emitInline`,
which controlled whether template scoping information for the NgModule was
emitted directly into the compiled NgModule definition, or whether an
associated statement was generated which patched the information onto the
NgModule definition. Both options are useful in different contexts.

This commit changes this flag to an enum (and renames it), which allows for
a third option - do not emit any template scoping information. This option
is added to better represent the actual behavior of the Angular Linker,
which sometimes configures `compileNgModule` to use the side-effectful
statement generation but which does not actually emit such associated
statements. In other words, the linker effectively does not generate
scoping information for NgModules at all (in some configurations) and this
option more directly expresses that behavior.

This is a refactoring as no generated code is changed as a result of
introducing this flag, due to the linker's behavior of not emitting
associated statements.

PR Close angular#45024

…ld (angular#45024)

When `@angular/compiler` processes metadata and compiles a definition field,
it might also choose to return statements that are associated with that
definition, and should be included after the type being compiled. Currently,
the linker ignores these statements, as there are none generated that are
relevant in the linking operation.

A challenge to supporting such associated statements is that the linker
operates on "declare" expressions, and replaces those expressions with other
expressions. It does not have the capability to append statements after the
whole type. The linker actually faces this challenge with statements from
the `ConstantPool` as well, and solves this problem by generating an IIFE
expression that executes the statements and then returns the definition
expression.

Previously, an `EmitScope` processed the definition and converted it to an
expression, as well as collected constant statements from a `ConstantPool`.
A special `IifeEmitScope` implementation was used when emitting into a
context where top-level constant statements couldn't be added at all, and
uses the IIFE strategy in this case.

This commit adds blanket support for associated statements to the linker
using this IIFE strategy. The main `EmitScope` now uses the IIFE strategy to
emit associated statements, and `IifeEmitScope` has been renamed to
`LocalEmitScope`. Now, the `LocalEmitScope` represents constant statements
as associated statements to the main `EmitScope` implementation, so they
get included in the IIFE as well.

Tests are adjusted/added to cover this new behavior. This is a refactoring
commit because no live generated code is affected - there are no cases where
associated statements are present in linked definitions today.

PR Close angular#45024

… ids (angular#45024)

Angular contains an NgModule registry, which allows a user to declare
NgModules with string ids and retrieve them via those ids, using the
`getNgModuleById` API.

Previously, we attempted to structure this registration in a clever fashion
to allow for tree-shaking of registered NgModules (that is, those with ids).
This sort of worked due to the accidental alignment of behaviors from the
different tree-shakers involved. However, this trick relies on the
generation of `.ngfactory` files and how they're specifically processed in
various bundling scenarios. We intend to remove `.ngfactory` files, hence
we can no longer rely on them in this way.

The correct solution here is to recognize that `@NgModule({id})` is
inherently declaring a global side-effect, and such classes should not
really be eligible for tree-shaking in the first place. This commit removes
all the old registration machinery, and standardizes on generating a side-
effectful call to `registerNgModuleType` for NgModules that have ids.

There is some risk here that NgModules with unnecessary `id`s may not
tree-shake as a result of this change, whereas they would have in previous
circumstances. The fix here should be to remove the `id` if it's not needed.
Specifying an `id` is a request that the NgModule be retained regardless of
any other references, in case it is later looked up by string id.

PR Close angular#45024

…gular#45024)

Previously, the `TraitCompiler` would naively consider a compilation as
failed if either analysis or resolution produced any diagnostics. This
commit adjusts the logic to only consider error diagnostics, which allows
warnings to be produced from `DecoratorHandler`s.

This is a precursor commit to introducing such a warning. As such, the
logic here will be tested in the next commit.

PR Close angular#45024

angular#45024)

In early versions of Angular, it was sometimes necessary to provide a
`moduleId` to `@Component` metadata, and the common pattern for doing this
was to set `moduleId: module.id`. This relied on the bundler to fill in a
value for `module.id`.

However, due to the superficial similarity between `Component.moduleId` and
`NgModule.id`, many users ended up setting `id: module.id` in their
NgModules. This is an anti-pattern that has a few negative effects,
including preventing the NgModule from tree-shaking properly.

This commit changes the compiler to ignore `id: module.id` in NgModules, and
instead provide a warning which suggests removing the line entirely.

PR Close angular#45024

…r#45024)

The `compileNgModule` operation previously supported a flag `emitInline`,
which controlled whether template scoping information for the NgModule was
emitted directly into the compiled NgModule definition, or whether an
associated statement was generated which patched the information onto the
NgModule definition. Both options are useful in different contexts.

This commit changes this flag to an enum (and renames it), which allows for
a third option - do not emit any template scoping information. This option
is added to better represent the actual behavior of the Angular Linker,
which sometimes configures `compileNgModule` to use the side-effectful
statement generation but which does not actually emit such associated
statements. In other words, the linker effectively does not generate
scoping information for NgModules at all (in some configurations) and this
option more directly expresses that behavior.

This is a refactoring as no generated code is changed as a result of
introducing this flag, due to the linker's behavior of not emitting
associated statements.

PR Close angular#45024

…ld (angular#45024)

When `@angular/compiler` processes metadata and compiles a definition field,
it might also choose to return statements that are associated with that
definition, and should be included after the type being compiled. Currently,
the linker ignores these statements, as there are none generated that are
relevant in the linking operation.

A challenge to supporting such associated statements is that the linker
operates on "declare" expressions, and replaces those expressions with other
expressions. It does not have the capability to append statements after the
whole type. The linker actually faces this challenge with statements from
the `ConstantPool` as well, and solves this problem by generating an IIFE
expression that executes the statements and then returns the definition
expression.

Previously, an `EmitScope` processed the definition and converted it to an
expression, as well as collected constant statements from a `ConstantPool`.
A special `IifeEmitScope` implementation was used when emitting into a
context where top-level constant statements couldn't be added at all, and
uses the IIFE strategy in this case.

This commit adds blanket support for associated statements to the linker
using this IIFE strategy. The main `EmitScope` now uses the IIFE strategy to
emit associated statements, and `IifeEmitScope` has been renamed to
`LocalEmitScope`. Now, the `LocalEmitScope` represents constant statements
as associated statements to the main `EmitScope` implementation, so they
get included in the IIFE as well.

Tests are adjusted/added to cover this new behavior. This is a refactoring
commit because no live generated code is affected - there are no cases where
associated statements are present in linked definitions today.

PR Close angular#45024

… ids (angular#45024)

Angular contains an NgModule registry, which allows a user to declare
NgModules with string ids and retrieve them via those ids, using the
`getNgModuleById` API.

Previously, we attempted to structure this registration in a clever fashion
to allow for tree-shaking of registered NgModules (that is, those with ids).
This sort of worked due to the accidental alignment of behaviors from the
different tree-shakers involved. However, this trick relies on the
generation of `.ngfactory` files and how they're specifically processed in
various bundling scenarios. We intend to remove `.ngfactory` files, hence
we can no longer rely on them in this way.

The correct solution here is to recognize that `@NgModule({id})` is
inherently declaring a global side-effect, and such classes should not
really be eligible for tree-shaking in the first place. This commit removes
all the old registration machinery, and standardizes on generating a side-
effectful call to `registerNgModuleType` for NgModules that have ids.

There is some risk here that NgModules with unnecessary `id`s may not
tree-shake as a result of this change, whereas they would have in previous
circumstances. The fix here should be to remove the `id` if it's not needed.
Specifying an `id` is a request that the NgModule be retained regardless of
any other references, in case it is later looked up by string id.

PR Close angular#45024

…gular#45024)

Previously, the `TraitCompiler` would naively consider a compilation as
failed if either analysis or resolution produced any diagnostics. This
commit adjusts the logic to only consider error diagnostics, which allows
warnings to be produced from `DecoratorHandler`s.

This is a precursor commit to introducing such a warning. As such, the
logic here will be tested in the next commit.

PR Close angular#45024

angular#45024)

In early versions of Angular, it was sometimes necessary to provide a
`moduleId` to `@Component` metadata, and the common pattern for doing this
was to set `moduleId: module.id`. This relied on the bundler to fill in a
value for `module.id`.

However, due to the superficial similarity between `Component.moduleId` and
`NgModule.id`, many users ended up setting `id: module.id` in their
NgModules. This is an anti-pattern that has a few negative effects,
including preventing the NgModule from tree-shaking properly.

This commit changes the compiler to ignore `id: module.id` in NgModules, and
instead provide a warning which suggests removing the line entirely.

PR Close angular#45024