add new rule: jsx-whitespace-literal

src/rules/jsxWhitespaceLiteralRule.ts

@@ -0,0 +1,53 @@
+/**
+ * @license
+ * Copyright 2017 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 { isJsxText } from "tsutils/typeguard/3.0";
+import * as ts from "typescript";
+
+const RESERVED_ENTITY = " ";
+
+export class Rule extends Lint.Rules.AbstractRule {
+    public static metadata: Lint.IRuleMetadata = {
+        description: Lint.Utils.dedent
+        `Warn if ' ' is used in JXS markup. Prefered {" "} over ' '`,
+        optionExamples: ["true"],
+        options: null,
+        optionsDescription: "",
+        ruleName: "jsx-whitespace-literal",
+        type: "functionality",
+        typescriptOnly: false,
+    };
+
+    public static FAILURE_STRING = `Prefered '{" "}' over ' ' in JSX markup.`;
+
+    public apply(sourceFile: ts.SourceFile): Lint.RuleFailure[] {
+        return this.applyWithFunction(sourceFile, walk);
+    }
+}
+
+function walk(ctx: Lint.WalkContext<void>): void {
+    return ts.forEachChild(ctx.sourceFile, function cb(node: ts.Node): void {
+        if (isJsxText(node)) {
+            if (node.getText().indexOf(RESERVED_ENTITY) > -1) {
+                ctx.addFailureAtNode(node, Rule.FAILURE_STRING);
+            }
+        }
+
+        return ts.forEachChild(node, cb);
+    });
+}

test/rules/jsx-whitespace-literal/test.tsx.lint

@@ -0,0 +1,29 @@
+<div>
+    <p>Some Text</p>
+    <hr></hr>
+    Some Text&nbsp;&nbsp;
+    ~~~~~~~~~~~~~~~~~~~~
+    <select>
+~~~~ [0]
+    <option></option>
+    </select>
+    <button type="button">Some Text</button>
+    <br/>
+    Some Text&nbsp;
+    ~~~~~~~~~~~~~~~
+    <select>
+~~~~ [0]
+    <option></option>
+    </select>
+    <button type="button">Some Text</button>
+    <br/>
+</div>
+
+<p>
+    <img src="images/img1.gif" width="50" height="50"/>&nbsp;
+                                                       ~~~~~~
+    <img src="images/img2.gif" width="50" height="50"/>
+~~~~ [0]
+</p>
+
+[0]: Prefered '{" "}' over '&nbsp;' in JSX markup.

test/rules/jsx-whitespace-literal/tslint.json

@@ -0,0 +1,5 @@
+{
+    "rules": {
+        "jsx-whitespace-literal": true
+    }
+}