feat(typescript-estree): [TS4.3] support overrides on class members (#3429)

Author: bradzacher

packages/ast-spec/src/base/ClassPropertyBase.ts

@@ -21,6 +21,7 @@ interface ClassPropertyBase extends BaseNode {
   optional?: boolean;
   definite?: boolean;
   typeAnnotation?: TSTypeAnnotation;
+  override?: boolean;
 }
 
 export interface ClassPropertyComputedNameBase extends ClassPropertyBase {

packages/ast-spec/src/base/MethodDefinitionBase.ts

@@ -21,6 +21,7 @@ interface MethodDefinitionBase extends BaseNode {
   decorators?: Decorator[];
   accessibility?: Accessibility;
   typeParameters?: TSTypeParameterDeclaration;
+  override?: boolean;
 }
 
 export interface MethodDefinitionComputedNameBase extends MethodDefinitionBase {

packages/shared-fixtures/fixtures/typescript/basics/abstract-class-with-override-method.src.ts

@@ -0,0 +1,3 @@
+abstract class SpecializedComponent extends SomeComponent {
+  abstract override show();
+}

packages/shared-fixtures/fixtures/typescript/basics/abstract-class-with-override-property.src.ts

@@ -0,0 +1,3 @@
+abstract class SpecializedComponent extends SomeComponent {
+  abstract override foo = 1;
+}

packages/shared-fixtures/fixtures/typescript/basics/class-with-override-method.src.ts

@@ -0,0 +1,5 @@
+class SpecializedComponent extends SomeComponent {
+  override show() {
+      // ...
+  }
+}

packages/shared-fixtures/fixtures/typescript/basics/class-with-override-property.src.ts

@@ -0,0 +1,3 @@
+class SpecializedComponent extends SomeComponent {
+  override foo = 1;
+}

packages/typescript-estree/src/convert.ts

@@ -1094,6 +1094,7 @@ export class Converter {
           static: hasModifier(SyntaxKind.StaticKeyword, node),
           readonly: hasModifier(SyntaxKind.ReadonlyKeyword, node) || undefined,
           declare: hasModifier(SyntaxKind.DeclareKeyword, node),
+          override: hasModifier(SyntaxKind.OverrideKeyword, node),
         });
 
         if (node.type) {
@@ -1209,6 +1210,7 @@ export class Converter {
             computed: isComputedProperty(node.name),
             static: hasModifier(SyntaxKind.StaticKeyword, node),
             kind: 'method',
+            override: hasModifier(SyntaxKind.OverrideKeyword, node),
           });
 
           if (node.decorators) {
@@ -1295,6 +1297,7 @@ export class Converter {
           computed: false,
           static: isStatic,
           kind: isStatic ? 'method' : 'constructor',
+          override: false,
         });
 
         const accessibility = getTSNodeAccessibility(node);

packages/typescript-estree/tests/ast-alignment/utils.ts

@@ -165,6 +165,13 @@ export function preprocessBabylonAST(ast: BabelTypes.File): any {
           node.type = AST_NODE_TYPES.TSAbstractMethodDefinition;
           delete node.abstract;
         }
+        /**
+         * TS 4.3: overrides on class members
+         * Babel doesn't ever emit a false override flag
+         */
+        if (node.override == null) {
+          node.override = false;
+        }
       },
       ClassProperty(node) {
         /**
@@ -183,6 +190,13 @@ export function preprocessBabylonAST(ast: BabelTypes.File): any {
         if (!node.declare) {
           node.declare = false;
         }
+        /**
+         * TS 4.3: overrides on class members
+         * Babel doesn't ever emit a false override flag
+         */
+        if (node.override == null) {
+          node.override = false;
+        }
       },
       TSExpressionWithTypeArguments(node, parent: any) {
         if (parent.type === AST_NODE_TYPES.TSInterfaceDeclaration) {

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

@@ -1679,6 +1679,10 @@ exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" e
 
 exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/basics/abstract-class-with-optional-method.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;
 
+exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/basics/abstract-class-with-override-method.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;
+
+exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/basics/abstract-class-with-override-property.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;
+
 exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/basics/abstract-interface.src 1`] = `
 TSError {
   "column": 7,
@@ -1800,6 +1804,10 @@ exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" e
 
 exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/basics/class-with-optional-property-undefined.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;
 
+exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/basics/class-with-override-method.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;
+
+exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/basics/class-with-override-property.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;
+
 exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/basics/class-with-private-parameter-properties.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;
 
 exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/basics/class-with-property-function.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;

packages/typescript-estree/tests/lib/__snapshots__/semanticInfo.test.ts.snap

@@ -1286,6 +1286,7 @@ Object {
                 "line": 4,
               },
             },
+            "override": false,
             "range": Array [
               39,
               56,