feat(compiler): support for singleline, multiline & jsdoc comments (#22715)

PR Close #22715

packages/compiler/src/compiler.ts

@@ -67,7 +67,7 @@ export * from './ml_parser/html_tags';
 export * from './ml_parser/interpolation_config';
 export * from './ml_parser/tags';
 export {NgModuleCompiler} from './ng_module_compiler';
-export {AssertNotNull, BinaryOperator, BinaryOperatorExpr, BuiltinMethod, BuiltinVar, CastExpr, ClassField, ClassMethod, ClassStmt, CommaExpr, CommentStmt, ConditionalExpr, DeclareFunctionStmt, DeclareVarStmt, ExpressionStatement, ExpressionVisitor, ExternalExpr, ExternalReference, FunctionExpr, IfStmt, InstantiateExpr, InvokeFunctionExpr, InvokeMethodExpr, LiteralArrayExpr, LiteralExpr, LiteralMapExpr, NotExpr, ReadKeyExpr, ReadPropExpr, ReadVarExpr, ReturnStatement, StatementVisitor, ThrowStmt, TryCatchStmt, WriteKeyExpr, WritePropExpr, WriteVarExpr, StmtModifier, Statement, collectExternalReferences} from './output/output_ast';
+export {AssertNotNull, BinaryOperator, BinaryOperatorExpr, BuiltinMethod, BuiltinVar, CastExpr, ClassField, ClassMethod, ClassStmt, CommaExpr, CommentStmt, ConditionalExpr, DeclareFunctionStmt, DeclareVarStmt, ExpressionStatement, ExpressionVisitor, ExternalExpr, ExternalReference, FunctionExpr, IfStmt, InstantiateExpr, InvokeFunctionExpr, InvokeMethodExpr, JSDocCommentStmt, LiteralArrayExpr, LiteralExpr, LiteralMapExpr, NotExpr, ReadKeyExpr, ReadPropExpr, ReadVarExpr, ReturnStatement, StatementVisitor, ThrowStmt, TryCatchStmt, WriteKeyExpr, WritePropExpr, WriteVarExpr, StmtModifier, Statement, collectExternalReferences} from './output/output_ast';
 export {EmitterVisitorContext} from './output/abstract_emitter';
 export * from './output/ts_emitter';
 export * from './parse_util';

packages/compiler/src/output/abstract_emitter.ts

@@ -233,10 +233,18 @@ export abstract class AbstractEmitterVisitor implements o.StatementVisitor, o.Ex
     return null;
   }
   visitCommentStmt(stmt: o.CommentStmt, ctx: EmitterVisitorContext): any {
-    const lines = stmt.comment.split('\n');
-    lines.forEach((line) => { ctx.println(stmt, `// ${line}`); });
+    if (stmt.multiline) {
+      ctx.println(stmt, `/* ${stmt.comment} */`);
+    } else {
+      stmt.comment.split('\n').forEach((line) => { ctx.println(stmt, `// ${line}`); });
+    }
     return null;
   }
+  visitJSDocCommentStmt(stmt: o.JSDocCommentStmt, ctx: EmitterVisitorContext) {
+    ctx.println(stmt, `/*${stmt.toString()}*/`);
+    return null;
+  }
+
   abstract visitDeclareVarStmt(stmt: o.DeclareVarStmt, ctx: EmitterVisitorContext): any;
 
   visitWriteVarExpr(expr: o.WriteVarExpr, ctx: EmitterVisitorContext): any {

packages/compiler/src/output/output_ast.ts

@@ -897,9 +897,8 @@ export class IfStmt extends Statement {
   }
 }
 
-
 export class CommentStmt extends Statement {
-  constructor(public comment: string, sourceSpan?: ParseSourceSpan|null) {
+  constructor(public comment: string, public multiline = false, sourceSpan?: ParseSourceSpan|null) {
     super(null, sourceSpan);
   }
   isEquivalent(stmt: Statement): boolean { return stmt instanceof CommentStmt; }
@@ -908,6 +907,18 @@ export class CommentStmt extends Statement {
   }
 }
 
+export class JSDocCommentStmt extends Statement {
+  constructor(public tags: JSDocTag[] = [], sourceSpan?: ParseSourceSpan|null) {
+    super(null, sourceSpan);
+  }
+  isEquivalent(stmt: Statement): boolean {
+    return stmt instanceof JSDocCommentStmt && this.toString() === stmt.toString();
+  }
+  visitStatement(visitor: StatementVisitor, context: any): any {
+    return visitor.visitJSDocCommentStmt(this, context);
+  }
+  toString(): string { return serializeTags(this.tags); }
+}
 
 export class TryCatchStmt extends Statement {
   constructor(
@@ -947,6 +958,7 @@ export interface StatementVisitor {
   visitTryCatchStmt(stmt: TryCatchStmt, context: any): any;
   visitThrowStmt(stmt: ThrowStmt, context: any): any;
   visitCommentStmt(stmt: CommentStmt, context: any): any;
+  visitJSDocCommentStmt(stmt: JSDocCommentStmt, context: any): any;
 }
 
 export class AstTransformer implements StatementVisitor, ExpressionVisitor {
@@ -1157,6 +1169,10 @@ export class AstTransformer implements StatementVisitor, ExpressionVisitor {
     return this.transformStmt(stmt, context);
   }
 
+  visitJSDocCommentStmt(stmt: JSDocCommentStmt, context: any): any {
+    return this.transformStmt(stmt, context);
+  }
+
   visitAllStatements(stmts: Statement[], context: any): Statement[] {
     return stmts.map(stmt => stmt.visitStatement(this, context));
   }
@@ -1321,6 +1337,7 @@ export class RecursiveAstVisitor implements StatementVisitor, ExpressionVisitor
     return stmt;
   }
   visitCommentStmt(stmt: CommentStmt, context: any): any { return stmt; }
+  visitJSDocCommentStmt(stmt: JSDocCommentStmt, context: any): any { return stmt; }
   visitAllStatements(stmts: Statement[], context: any): void {
     stmts.forEach(stmt => stmt.visitStatement(this, context));
   }
@@ -1467,3 +1484,54 @@ export function literal(
     value: any, type?: Type | null, sourceSpan?: ParseSourceSpan | null): LiteralExpr {
   return new LiteralExpr(value, type, sourceSpan);
 }
+
+// The list of JSDoc tags that we currently support. Extend it if needed.
+export const enum JSDocTagName {Desc = 'desc', Id = 'id', Meaning = 'meaning'}
+
+/*
+ * TypeScript has an API for JSDoc already, but it's not exposed.
+ * https://github.com/Microsoft/TypeScript/issues/7393
+ * For now we create types that are similar to theirs so that migrating
+ * to their API will be easier. See e.g. `ts.JSDocTag` and `ts.JSDocComment`.
+ */
+export type JSDocTag = {
+  // `tagName` is e.g. "param" in an `@param` declaration
+  tagName: JSDocTagName | string;
+  // Any remaining text on the tag, e.g. the description
+  text?: string;
+} | {// no `tagName` for plain text documentation that occurs before any `@param` lines
+     tagName?: undefined
+  text: string,
+};
+
+  /*
+   * Serializes a `Tag` into a string.
+   * Returns a string like " @foo {bar} baz" (note the leading whitespace before `@foo`).
+   */
+  function tagToString(tag: JSDocTag): string {
+    let out = '';
+    if (tag.tagName) {
+      out += ` @${tag.tagName}`;
+    }
+    if (tag.text) {
+      if (tag.text.match(/\/\*|\*\//)) {
+        throw new Error('JSDoc text cannot contain "/*" and "*/"');
+      }
+      out += ' ' + tag.text.replace(/@/g, '\\@');
+    }
+    return out;
+  }
+
+  function serializeTags(tags: JSDocTag[]): string {
+    if (tags.length === 0) return '';
+
+    let out = '*\n';
+    for (const tag of tags) {
+      out += ' *';
+      // If the tagToString is multi-line, insert " * " prefixes on subsequent lines.
+      out += tagToString(tag).replace(/\n/g, '\n * ');
+      out += '\n';
+    }
+    out += ' ';
+    return out;
+  }

packages/compiler/src/output/output_interpreter.ts

@@ -226,6 +226,7 @@ class StatementInterpreter implements o.StatementVisitor, o.ExpressionVisitor {
     throw stmt.error.visitExpression(this, ctx);
   }
   visitCommentStmt(stmt: o.CommentStmt, context?: any): any { return null; }
+  visitJSDocCommentStmt(stmt: o.JSDocCommentStmt, context?: any): any { return null; }
   visitInstantiateExpr(ast: o.InstantiateExpr, ctx: _ExecutionContext): any {
     const args = this.visitAllExpressions(ast.args, ctx);
     const clazz = ast.classExpr.visitExpression(this, ctx);