class-name: Refactor and check class expressions (palantir#2553)

[enhancement] `class-name` now also checks class expressions
Pringmore · Apr 12, 2017 · 33e672f · 33e672f
1 parent bdd8e54
commit 33e672f
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Showing 2 changed files with 23 additions and 28 deletions.
diff --git a/src/rules/classNameRule.ts b/src/rules/classNameRule.ts
@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+import { isClassLikeDeclaration, isInterfaceDeclaration } from "tsutils";
 import * as ts from "typescript";
 
 import * as Lint from "../index";
@@ -36,38 +37,23 @@ export class Rule extends Lint.Rules.AbstractRule {
     public static FAILURE_STRING = "Class name must be in pascal case";
 
     public apply(sourceFile: ts.SourceFile): Lint.RuleFailure[] {
-        return this.applyWithWalker(new NameWalker(sourceFile, this.getOptions()));
+        return this.applyWithFunction(sourceFile, walk);
     }
 }
 
-class NameWalker extends Lint.RuleWalker {
-    public visitClassDeclaration(node: ts.ClassDeclaration) {
-        // classes declared as default exports will be unnamed
-        if (node.name != null) {
-            const className = node.name.getText();
-            if (!this.isPascalCased(className)) {
-                this.addFailureAtNode(node.name, Rule.FAILURE_STRING);
+function walk(ctx: Lint.WalkContext<void>) {
+    return ts.forEachChild(ctx.sourceFile, function cb(node: ts.Node): void {
+        if (isClassLikeDeclaration(node) && node.name !== undefined ||
+            isInterfaceDeclaration(node)) {
+            if (!isPascalCased(node.name!.text)) {
+                ctx.addFailureAtNode(node.name!, Rule.FAILURE_STRING);
             }
         }
+        return ts.forEachChild(node, cb);
+    });
+}
 
-        super.visitClassDeclaration(node);
-    }
-
-    public visitInterfaceDeclaration(node: ts.InterfaceDeclaration) {
-        const interfaceName = node.name.getText();
-        if (!this.isPascalCased(interfaceName)) {
-            this.addFailureAtNode(node.name, Rule.FAILURE_STRING);
-        }
-
-        super.visitInterfaceDeclaration(node);
-    }
-
-    private isPascalCased(name: string) {
-        if (name.length <= 0) {
-            return true;
-        }
-
-        const firstCharacter = name.charAt(0);
-        return ((firstCharacter === firstCharacter.toUpperCase()) && name.indexOf("_") === -1);
-    }
+function isPascalCased(name: string) {
+    const firstCharacter = name[0];
+    return ((firstCharacter === firstCharacter.toUpperCase()) && !name.includes("_"));
 }
diff --git a/test/rules/class-name/test.ts.lint b/test/rules/class-name/test.ts.lint
@@ -14,4 +14,13 @@ export default class {
     // should not fail
 }
 
+// anonymous class expression
+var foo = class {};
+var bar = class invalidName {}
+                ~~~~~~~~~~~ [0]
+
+interface someInterface {}
+          ~~~~~~~~~~~~~ [0]
+interface SomeInterface {}
+
 [0]: Class name must be in pascal case