refactor(compiler-cli): make file/shim split 1:n instead of 1:1 (angular#38105)

Previously in the template type-checking engine, it was assumed that every
input file would have an associated type-checking shim. The type check block
code for all components in the input file would be generated into this shim.

This is fine for whole-program type checking operations, but to support the
language service's requirements for low latency, it would be ideal to be
able to check a single component in isolation, especially if the component
is declared along with many others in a single file.

This commit removes the assumption that the file/shim mapping is 1:1, and
introduces the concept of component-to-shim mapping. Any
`TypeCheckingProgramStrategy` must provide such a mapping.

To achieve this:

 * type checking record information is now split into file-level data as
   well as per-shim data.
 * components are now assigned a stable `TemplateId` which is unique to the
   file in which they're declared.

PR Close angular#38105

Author: alxhub

packages/compiler-cli/src/ngtsc/incremental/api.ts

@@ -12,21 +12,21 @@ import {AbsoluteFsPath} from '../file_system';
 /**
  * Interface of the incremental build engine.
  *
- * `W` is a generic type representing a unit of work. This is generic to avoid a cyclic dependency
- * between the incremental engine API definition and its consumer(s).
- * `T` is a generic type representing template type-checking data for a particular file, which is
- * generic for the same reason.
+ * `AnalysisT` is a generic type representing a unit of work. This is generic to avoid a cyclic
+ * dependency between the incremental engine API definition and its consumer(s).
+ * `FileTypeCheckDataT` is a generic type representing template type-checking data for a particular
+ * input file, which is generic for the same reason.
  */
-export interface IncrementalBuild<W, T> {
+export interface IncrementalBuild<AnalysisT, FileTypeCheckDataT> {
   /**
    * Retrieve the prior analysis work, if any, done for the given source file.
    */
-  priorWorkFor(sf: ts.SourceFile): W[]|null;
+  priorWorkFor(sf: ts.SourceFile): AnalysisT[]|null;
 
   /**
    * Retrieve the prior type-checking work, if any, that's been done for the given source file.
    */
-  priorTypeCheckingResultsFor(sf: ts.SourceFile): T|null;
+  priorTypeCheckingResultsFor(fileSf: ts.SourceFile): FileTypeCheckDataT|null;
 }
 
 /**

packages/compiler-cli/src/ngtsc/typecheck/src/api.ts

@@ -13,6 +13,7 @@ import {AbsoluteFsPath} from '../../file_system';
 import {Reference} from '../../imports';
 import {TemplateGuardMeta} from '../../metadata';
 import {ClassDeclaration} from '../../reflection';
+import {ComponentToShimMappingStrategy} from './context';
 
 
 /**
@@ -284,7 +285,7 @@ export interface ExternalTemplateSourceMapping {
  * This abstraction allows both the Angular compiler itself as well as the language service to
  * implement efficient template type-checking using common infrastructure.
  */
-export interface TypeCheckingProgramStrategy {
+export interface TypeCheckingProgramStrategy extends ComponentToShimMappingStrategy {
   /**
    * Retrieve the latest version of the program, containing all the updates made thus far.
    */

packages/compiler-cli/src/ngtsc/typecheck/src/augmented_program.ts

@@ -8,11 +8,12 @@
 
 import * as ts from 'typescript';
 
-import {AbsoluteFsPath} from '../../file_system';
+import {absoluteFromSourceFile, AbsoluteFsPath} from '../../file_system';
 import {retagAllTsFiles, untagAllTsFiles} from '../../shims';
 
 import {TypeCheckingProgramStrategy, UpdateMode} from './api';
 import {TypeCheckProgramHost} from './host';
+import {TypeCheckShimGenerator} from './shim';
 
 /**
  * Implements a template type-checking program using `ts.createProgram` and TypeScript's program
@@ -78,4 +79,8 @@ export class ReusedProgramStrategy implements TypeCheckingProgramStrategy {
     untagAllTsFiles(this.program);
     untagAllTsFiles(oldProgram);
   }
+
+  shimPathForComponent(node: ts.ClassDeclaration): AbsoluteFsPath {
+    return TypeCheckShimGenerator.shimFor(absoluteFromSourceFile(node.getSourceFile()));
+  }
 }

packages/compiler-cli/src/ngtsc/typecheck/src/checker.ts

@@ -16,7 +16,7 @@ import {isShim} from '../../shims';
 
 import {TypeCheckingConfig, TypeCheckingProgramStrategy, UpdateMode} from './api';
 import {FileTypeCheckingData, TypeCheckContext, TypeCheckRequest} from './context';
-import {shouldReportDiagnostic, translateDiagnostic} from './diagnostics';
+import {shouldReportDiagnostic, TemplateSourceResolver, translateDiagnostic} from './diagnostics';
 
 /**
  * Interface to trigger generation of type-checking code for a program given a new
@@ -49,8 +49,8 @@ export class TemplateTypeChecker {
   refresh(): TypeCheckRequest {
     this.files.clear();
 
-    const ctx =
-        new TypeCheckContext(this.config, this.compilerHost, this.refEmitter, this.reflector);
+    const ctx = new TypeCheckContext(
+        this.config, this.compilerHost, this.typeCheckingStrategy, this.refEmitter, this.reflector);
 
     // Typecheck all the files.
     for (const sf of this.originalProgram.getSourceFiles()) {
@@ -86,25 +86,32 @@ export class TemplateTypeChecker {
     if (!this.files.has(path)) {
       return [];
     }
-    const record = this.files.get(path)!;
+    const fileRecord = this.files.get(path)!;
 
     const typeCheckProgram = this.typeCheckingStrategy.getProgram();
-    const typeCheckSf = getSourceFileOrError(typeCheckProgram, record.typeCheckFile);
-    const rawDiagnostics = [];
-    rawDiagnostics.push(...typeCheckProgram.getSemanticDiagnostics(typeCheckSf));
-    if (record.hasInlines) {
+
+    const diagnostics: (ts.Diagnostic|null)[] = [];
+    if (fileRecord.hasInlines) {
       const inlineSf = getSourceFileOrError(typeCheckProgram, path);
-      rawDiagnostics.push(...typeCheckProgram.getSemanticDiagnostics(inlineSf));
+      diagnostics.push(...typeCheckProgram.getSemanticDiagnostics(inlineSf).map(
+          diag => convertDiagnostic(diag, fileRecord.sourceResolver)));
+    }
+    for (const [shimPath, shimRecord] of fileRecord.shimData) {
+      const shimSf = getSourceFileOrError(typeCheckProgram, shimPath);
+
+      diagnostics.push(...typeCheckProgram.getSemanticDiagnostics(shimSf).map(
+          diag => convertDiagnostic(diag, fileRecord.sourceResolver)));
+      diagnostics.push(...shimRecord.genesisDiagnostics);
     }
 
-    return rawDiagnostics
-        .map(diag => {
-          if (!shouldReportDiagnostic(diag)) {
-            return null;
-          }
-          return translateDiagnostic(diag, record.sourceResolver);
-        })
-        .filter((diag: ts.Diagnostic|null): diag is ts.Diagnostic => diag !== null)
-        .concat(record.genesisDiagnostics);
+    return diagnostics.filter((diag: ts.Diagnostic|null): diag is ts.Diagnostic => diag !== null);
+  }
+}
+
+function convertDiagnostic(
+    diag: ts.Diagnostic, sourceResolver: TemplateSourceResolver): ts.Diagnostic|null {
+  if (!shouldReportDiagnostic(diag)) {
+    return null;
   }
+  return translateDiagnostic(diag, sourceResolver);
 }

packages/compiler-cli/src/ngtsc/typecheck/src/context.ts

@@ -14,12 +14,11 @@ import {NoopImportRewriter, Reference, ReferenceEmitter} from '../../imports';
 import {ClassDeclaration, ReflectionHost} from '../../reflection';
 import {ImportManager} from '../../translator';
 
-import {TemplateSourceMapping, TypeCheckableDirectiveMeta, TypeCheckBlockMetadata, TypeCheckingConfig, TypeCtorMetadata} from './api';
+import {TemplateId, TemplateSourceMapping, TypeCheckableDirectiveMeta, TypeCheckBlockMetadata, TypeCheckingConfig, TypeCtorMetadata} from './api';
 import {TemplateSourceResolver} from './diagnostics';
 import {DomSchemaChecker, RegistryDomSchemaChecker} from './dom';
 import {Environment} from './environment';
 import {OutOfBandDiagnosticRecorder, OutOfBandDiagnosticRecorderImpl} from './oob';
-import {TypeCheckShimGenerator} from './shim';
 import {TemplateSourceManager} from './source';
 import {generateTypeCheckBlock, requiresInlineTypeCheckBlock} from './type_check_block';
 import {TypeCheckFile} from './type_check_file';
@@ -46,7 +45,8 @@ export interface TypeCheckRequest {
 }
 
 /**
- * Data for a type-checking shim which is required to support generation of diagnostics.
+ * Data for template type-checking related to a specific input file in the user's program (which
+ * contains components to be checked).
  */
 export interface FileTypeCheckingData {
   /**
@@ -56,25 +56,39 @@ export interface FileTypeCheckingData {
   hasInlines: boolean;
 
   /**
-   * Source mapping information for mapping diagnostics back to the original template.
+   * Source mapping information for mapping diagnostics from inlined type check blocks back to the
+   * original template.
    */
   sourceResolver: TemplateSourceResolver;
 
   /**
-   * Any `ts.Diagnostic`s which were produced during the generation of this shim.
+   * Data for each shim generated from this input file.
    *
-   * Some diagnostics are produced during creation time and are tracked here.
+   * A single input file will generate one or more shim files that actually contain template
+   * type-checking code.
    */
-  genesisDiagnostics: ts.Diagnostic[];
+  shimData: Map<AbsoluteFsPath, ShimTypeCheckingData>;
+}
 
+/**
+ * Data specific to a single shim generated from an input file.
+ */
+export interface ShimTypeCheckingData {
   /**
    * Path to the shim file.
    */
-  typeCheckFile: AbsoluteFsPath;
+  path: AbsoluteFsPath;
+
+  /**
+   * Any `ts.Diagnostic`s which were produced during the generation of this shim.
+   *
+   * Some diagnostics are produced during creation time and are tracked here.
+   */
+  genesisDiagnostics: ts.Diagnostic[];
 }
 
 /**
- * Data for a type-checking shim which is still having its code generated.
+ * Data for an input file which is still in the process of template type-checking code generation.
  */
 export interface PendingFileTypeCheckingData {
   /**
@@ -83,10 +97,18 @@ export interface PendingFileTypeCheckingData {
   hasInlines: boolean;
 
   /**
-   * `TemplateSourceManager` being used to track source mapping information for this shim.
+   * Source mapping information for mapping diagnostics from inlined type check blocks back to the
+   * original template.
    */
   sourceManager: TemplateSourceManager;
 
+  /**
+   * Map of in-progress shim data for shims generated from this input file.
+   */
+  shimData: Map<AbsoluteFsPath, PendingShimData>;
+}
+
+export interface PendingShimData {
   /**
    * Recorder for out-of-band diagnostics which are raised during generation.
    */
@@ -98,9 +120,28 @@ export interface PendingFileTypeCheckingData {
   domSchemaChecker: DomSchemaChecker;
 
   /**
-   * Path to the shim file.
+   * Shim file in the process of being generated.
    */
-  typeCheckFile: TypeCheckFile;
+  file: TypeCheckFile;
+}
+
+/**
+ * Abstracts the operation of determining which shim file will host a particular component's
+ * template type-checking code.
+ *
+ * Different consumers of the type checking infrastructure may choose different approaches to
+ * optimize for their specific use case (for example, the command-line compiler optimizes for
+ * efficient `ts.Program` reuse in watch mode).
+ */
+export interface ComponentToShimMappingStrategy {
+  /**
+   * Given a component, determine a path to the shim file into which that component's type checking
+   * code will be generated.
+   *
+   * A major constraint is that components in different input files must not share the same shim
+   * file. The behavior of the template type-checking system is undefined if this is violated.
+   */
+  shimPathForComponent(node: ts.ClassDeclaration): AbsoluteFsPath;
 }
 
 /**
@@ -115,6 +156,7 @@ export class TypeCheckContext {
   constructor(
       private config: TypeCheckingConfig,
       private compilerHost: Pick<ts.CompilerHost, 'getCanonicalFileName'>,
+      private componentMappingStrategy: ComponentToShimMappingStrategy,
       private refEmitter: ReferenceEmitter, private reflector: ReflectionHost) {}
 
   /**
@@ -160,8 +202,7 @@ export class TypeCheckContext {
       schemas: SchemaMetadata[], sourceMapping: TemplateSourceMapping,
       file: ParseSourceFile): void {
     const fileData = this.dataForFile(ref.node.getSourceFile());
-
-    const id = fileData.sourceManager.captureSource(sourceMapping, file);
+    const shimData = this.pendingShimForComponent(ref.node);
     // Get all of the directives used in the template and record type constructors for all of them.
     for (const dir of boundTarget.getUsedDirectives()) {
       const dirRef = dir.ref as Reference<ClassDeclaration<ts.ClassDeclaration>>;
@@ -184,15 +225,19 @@ export class TypeCheckContext {
       }
     }
 
-    const tcbMetadata: TypeCheckBlockMetadata = {id, boundTarget, pipes, schemas};
+    const meta = {
+      id: fileData.sourceManager.captureSource(ref.node, sourceMapping, file),
+      boundTarget,
+      pipes,
+      schemas,
+    };
     if (requiresInlineTypeCheckBlock(ref.node)) {
       // This class didn't meet the requirements for external type checking, so generate an inline
       // TCB for the class.
-      this.addInlineTypeCheckBlock(fileData, ref, tcbMetadata);
+      this.addInlineTypeCheckBlock(fileData, shimData, ref, meta);
     } else {
       // The class can be type-checked externally as normal.
-      fileData.typeCheckFile.addTypeCheckBlock(
-          ref, tcbMetadata, fileData.domSchemaChecker, fileData.oobRecorder);
+      shimData.file.addTypeCheckBlock(ref, meta, shimData.domSchemaChecker, shimData.oobRecorder);
     }
   }
 
@@ -278,17 +323,27 @@ export class TypeCheckContext {
       perFileData: new Map<AbsoluteFsPath, FileTypeCheckingData>(),
     };
 
-    for (const [sfPath, fileData] of this.fileMap.entries()) {
-      updates.set(fileData.typeCheckFile.fileName, fileData.typeCheckFile.render());
-      results.perFileData.set(sfPath, {
-        genesisDiagnostics: [
-          ...fileData.domSchemaChecker.diagnostics,
-          ...fileData.oobRecorder.diagnostics,
-        ],
-        hasInlines: fileData.hasInlines,
-        sourceResolver: fileData.sourceManager,
-        typeCheckFile: fileData.typeCheckFile.fileName,
-      });
+    // Then go through each input file that has pending code generation operations.
+    for (const [sfPath, pendingFileData] of this.fileMap) {
+      const fileData: FileTypeCheckingData = {
+        hasInlines: pendingFileData.hasInlines,
+        shimData: new Map(),
+        sourceResolver: pendingFileData.sourceManager,
+      };
+
+      // For each input file, consider generation operations for each of its shims.
+      for (const [shimPath, pendingShimData] of pendingFileData.shimData) {
+        updates.set(pendingShimData.file.fileName, pendingShimData.file.render());
+        fileData.shimData.set(shimPath, {
+          genesisDiagnostics: [
+            ...pendingShimData.domSchemaChecker.diagnostics,
+            ...pendingShimData.oobRecorder.diagnostics,
+          ],
+          path: pendingShimData.file.fileName,
+        });
+      }
+
+      results.perFileData.set(sfPath, fileData);
     }
 
     for (const [sfPath, fileData] of this.adoptedFiles.entries()) {
@@ -299,32 +354,44 @@ export class TypeCheckContext {
   }
 
   private addInlineTypeCheckBlock(
-      fileData: PendingFileTypeCheckingData, ref: Reference<ClassDeclaration<ts.ClassDeclaration>>,
+      fileData: PendingFileTypeCheckingData, shimData: PendingShimData,
+      ref: Reference<ClassDeclaration<ts.ClassDeclaration>>,
       tcbMeta: TypeCheckBlockMetadata): void {
     const sf = ref.node.getSourceFile();
     if (!this.opMap.has(sf)) {
       this.opMap.set(sf, []);
     }
     const ops = this.opMap.get(sf)!;
     ops.push(new TcbOp(
-        ref, tcbMeta, this.config, this.reflector, fileData.domSchemaChecker,
-        fileData.oobRecorder));
+        ref, tcbMeta, this.config, this.reflector, shimData.domSchemaChecker,
+        shimData.oobRecorder));
     fileData.hasInlines = true;
   }
 
+  private pendingShimForComponent(node: ts.ClassDeclaration): PendingShimData {
+    const fileData = this.dataForFile(node.getSourceFile());
+    const shimPath = this.componentMappingStrategy.shimPathForComponent(node);
+    if (!fileData.shimData.has(shimPath)) {
+      fileData.shimData.set(shimPath, {
+        domSchemaChecker: new RegistryDomSchemaChecker(fileData.sourceManager),
+        oobRecorder: new OutOfBandDiagnosticRecorderImpl(fileData.sourceManager),
+        file: new TypeCheckFile(
+            shimPath, this.config, this.refEmitter, this.reflector, this.compilerHost),
+      });
+    }
+    return fileData.shimData.get(shimPath)!;
+  }
+
   private dataForFile(sf: ts.SourceFile): PendingFileTypeCheckingData {
     const sfPath = absoluteFromSourceFile(sf);
 
+    const sourceManager = new TemplateSourceManager();
+
     if (!this.fileMap.has(sfPath)) {
-      const sourceManager = new TemplateSourceManager();
       const data: PendingFileTypeCheckingData = {
-        domSchemaChecker: new RegistryDomSchemaChecker(sourceManager),
-        oobRecorder: new OutOfBandDiagnosticRecorderImpl(sourceManager),
-        typeCheckFile: new TypeCheckFile(
-            TypeCheckShimGenerator.shimFor(sfPath), this.config, this.refEmitter, this.reflector,
-            this.compilerHost),
         hasInlines: false,
         sourceManager,
+        shimData: new Map(),
       };
       this.fileMap.set(sfPath, data);
     }