feat(typescript-estree): support type annotations on catch clauses

packages/shared-fixtures/fixtures/typescript/basics/catch-clause-with-annotation.src.ts

@@ -0,0 +1,11 @@
+try {
+
+} catch (e: any) {
+
+}
+
+try {
+
+} catch (e: unknown) {
+
+}

packages/shared-fixtures/fixtures/typescript/basics/catch-clause-with-invalid-annotation.src.ts

@@ -0,0 +1,5 @@
+try {
+
+} catch (e: string) {
+
+}

packages/typescript-estree/src/convert.ts

@@ -258,6 +258,21 @@ export class Converter {
     return result as T;
   }
 
+  private convertBindingNameWithTypeAnnotation(
+    name: ts.BindingName,
+    tsType: ts.TypeNode | undefined,
+    parent?: ts.Node,
+  ): TSESTree.BindingName {
+    const id = this.convertPattern(name);
+
+    if (tsType) {
+      id.typeAnnotation = this.convertTypeAnnotation(tsType, parent);
+      this.fixParentLocation(id, id.typeAnnotation.range);
+    }
+
+    return id;
+  }
+
   /**
    * Converts a child into a type annotation. This creates an intermediary
    * TypeAnnotation node to match what Flow does.
@@ -267,12 +282,12 @@ export class Converter {
    */
   private convertTypeAnnotation(
     child: ts.TypeNode,
-    parent: ts.Node,
+    parent: ts.Node | undefined,
   ): TSESTree.TSTypeAnnotation {
     // in FunctionType and ConstructorType typeAnnotation has 2 characters `=>` and in other places is just colon
     const offset =
-      parent.kind === SyntaxKind.FunctionType ||
-      parent.kind === SyntaxKind.ConstructorType
+      parent?.kind === SyntaxKind.FunctionType ||
+      parent?.kind === SyntaxKind.ConstructorType
         ? 2
         : 1;
     const annotationStartCol = child.getFullStart() - offset;
@@ -697,7 +712,10 @@ export class Converter {
         return this.createNode<TSESTree.CatchClause>(node, {
           type: AST_NODE_TYPES.CatchClause,
           param: node.variableDeclaration
-            ? this.convertChild(node.variableDeclaration.name)
+            ? this.convertBindingNameWithTypeAnnotation(
+                node.variableDeclaration.name,
+                node.variableDeclaration.type,
+              )
             : null,
           body: this.convertChild(node.block),
         });
@@ -805,21 +823,18 @@ export class Converter {
       case SyntaxKind.VariableDeclaration: {
         const result = this.createNode<TSESTree.VariableDeclarator>(node, {
           type: AST_NODE_TYPES.VariableDeclarator,
-          id: this.convertPattern(node.name),
+          id: this.convertBindingNameWithTypeAnnotation(
+            node.name,
+            node.type,
+            node,
+          ),
           init: this.convertChild(node.initializer),
         });
 
         if (node.exclamationToken) {
           result.definite = true;
         }
 
-        if (node.type) {
-          result.id.typeAnnotation = this.convertTypeAnnotation(
-            node.type,
-            node,
-          );
-          this.fixParentLocation(result.id, result.id.typeAnnotation.range);
-        }
         return result;
       }
 

packages/typescript-estree/src/semantic-or-syntactic-errors.ts

@@ -81,6 +81,7 @@ function whitelistSupportedDiagnostics(
       case 1175: // "'implements' clause already seen."
       case 1176: // "Interface declaration cannot have 'implements' clause."
       case 1190: // "The variable declaration of a 'for...of' statement cannot have an initializer."
+      case 1196: // "Catch clause variable type annotation must be 'any' or 'unknown' if specified."
       case 1200: // "Line terminator not permitted before arrow."
       case 1206: // "Decorators are not valid here."
       case 1211: // "A class declaration without the 'default' modifier must have a name."

packages/typescript-estree/tests/ast-alignment/fixtures-to-test.ts

@@ -418,6 +418,12 @@ tester.addFixturePatternConfig('typescript/basics', {
      * babel uses a representation that does not match the ESTree spec: https://github.com/estree/estree/pull/205
      */
     'export-star-as-ns-from',
+    /**
+     * TS 4.0 catch clause with type annotation
+     * Not supported in babel yet
+     */
+    'catch-clause-with-annotation',
+    'catch-clause-with-invalid-annotation',
   ],
   ignoreSourceType: [
     /**

packages/typescript-estree/tests/lib/__snapshots__/semantic-diagnostics-enabled.test.ts.snap

@@ -1736,6 +1736,17 @@ exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" e
 
 exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/basics/cast-as-simple.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;
 
+exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/basics/catch-clause-with-annotation.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;
+
+exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/basics/catch-clause-with-invalid-annotation.src 1`] = `
+Object {
+  "column": 12,
+  "index": 19,
+  "lineNumber": 3,
+  "message": "Catch clause variable type annotation must be 'any' or 'unknown' if specified.",
+}
+`;
+
 exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/basics/class-multi-line-keyword-abstract.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;
 
 exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/basics/class-multi-line-keyword-declare.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;