Add new rule (no space before '>')

README.md

@@ -83,6 +83,9 @@ The built-in configuration preset you get with `"extends": "tslint-react"` is se
 - `jsx-no-multiline-js`
   - Disallows multiline JS expressions inside JSX blocks to promote readability
   - Rule options: _none_
+- `jsx-no-space-before-end-of-tag`
+  - Checks that JSX elements do not have a space before the '>' part.
+  - Rule options: _none_
 - `jsx-no-string-ref`
   - Passing strings to the `ref` prop of React elements is considered a legacy feature and will soon be deprecated.
     Instead, [use a callback](https://facebook.github.io/react/docs/more-about-refs.html#the-ref-callback-attribute).

src/rules/jsxNoSpaceBeforeEndOfTagRule.ts

@@ -0,0 +1,56 @@
+/**
+ * @license
+ * Copyright 2016 Palantir Technologies, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import * as Lint from "tslint";
+import { isJsxSelfClosingElement } from "tsutils";
+import * as ts from "typescript";
+
+export class Rule extends Lint.Rules.AbstractRule {
+    /* tslint:disable:object-literal-sort-keys */
+    public static metadata: Lint.IRuleMetadata = {
+        ruleName: "jsx-no-space-before-end-of-tag",
+        description: "Checks that JSX elements do not have a space before the '>' part.",
+        options: null,
+        optionsDescription: "",
+        optionExamples: ["true"],
+        type: "style",
+        typescriptOnly: false,
+    };
+    /* tslint:enable:object-literal-sort-keys */
+
+    public static FAILURE_STRING = "JSX elements must not have a space before the '>' part";
+
+    public apply(sourceFile: ts.SourceFile): Lint.RuleFailure[] {
+        return this.applyWithFunction(sourceFile, walk);
+    }
+}
+
+const closingLength = ">".length;
+const isWhiteSpace = (char: string) => /\s/.test(char);
+const hasWhitespaceBeforeClosing = (nodeText: string) =>
+    isWhiteSpace(nodeText.charAt(nodeText.length - closingLength - 1));
+
+function walk(ctx: Lint.WalkContext<void>): void {
+    return ts.forEachChild(ctx.sourceFile, function cb(node: ts.Node): void {
+        if (isJsxSelfClosingElement(node)) {
+            if (hasWhitespaceBeforeClosing(node.getText(ctx.sourceFile))) {
+                ctx.addFailureAtNode(node, Rule.FAILURE_STRING);
+            }
+        }
+        return ts.forEachChild(node, cb);
+    });
+}