feat: add jsx-whitespace-literal rule (#243)

Author: tanmoyopenroot

src/rules/jsxWhitespaceLiteralRule.ts

@@ -0,0 +1,92 @@
+/**
+ * @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. Prefer {" "} over ' '`,
+        optionExamples: ["true"],
+        options: null,
+        optionsDescription: "",
+        ruleName: "jsx-whitespace-literal",
+        type: "functionality",
+        typescriptOnly: false,
+    };
+
+    public static FAILURE_STRING = `Expected '{" "}' instead of ' ' in JSX markup`;
+
+    public apply(sourceFile: ts.SourceFile): Lint.RuleFailure[] {
+        return this.applyWithFunction(sourceFile, walk);
+    }
+}
+
+function getSpaces(numOfSpaces: number): string {
+    return " ".repeat(numOfSpaces);
+}
+
+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) {
+                const text: string = node.getText();
+                const regex: RegExp = new RegExp(RESERVED_ENTITY, "g");
+                const startIndices: number[] = [];
+                const endIndices: number[] = [];
+                let countEnitiy: number = -1;
+                let result: RegExpExecArray | null;
+
+                do {
+                    result = regex.exec(text);
+                    if (result !== null) {
+                        if (
+                            startIndices[countEnitiy] !== undefined &&
+                            endIndices[countEnitiy] !== undefined &&
+                            startIndices[countEnitiy] + endIndices[countEnitiy] === result.index
+                        ) {
+                            endIndices[countEnitiy] = endIndices[countEnitiy] + RESERVED_ENTITY.length;
+                        } else {
+                            startIndices.push(result.index);
+                            endIndices.push(RESERVED_ENTITY.length);
+                            countEnitiy += 1;
+                        }
+                    }
+                } while (result !== null);
+
+                startIndices.forEach((startIndex, index) => {
+                    const start = node.getStart() + startIndex;
+                    const end = endIndices[index];
+                    const fix = Lint.Replacement.replaceFromTo(
+                        start,
+                        start + end,
+                        `{"${getSpaces(end / RESERVED_ENTITY.length)}"}`,
+                    );
+
+                    ctx.addFailureAt(start, end, Rule.FAILURE_STRING, fix);
+
+                });
+            }
+        }
+
+        return ts.forEachChild(node, cb);
+    });
+}

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

@@ -0,0 +1,35 @@
+<div>
+    <p>Some Text</p>
+    <hr></hr>
+    Some Text{"  "}
+    <select>
+    <option></option>
+    </select>
+    <button type="button">Some Text</button>
+    <button type="button">Some Text{" "}</button>
+    <button type="button">Some Text {" "} </button>
+    <button type="button">Some Text &NBSP; </button>
+    <button type="button">Some Text &nBSP; </button>
+    <br/>
+    Some Text{" "}
+    <select>
+    <option></option>
+    </select>
+    <button type="button">Some Text{"    "}</button>
+    <button type="button">Some Text {"    "} </button>
+    <hr></hr>
+    Some Text{"   "}
+    <br/>
+    <button type="button">
+        Some Text{" "}
+    </button>
+    <button type="button">
+        Some Text{"    "}
+    </button>
+</div>
+
+<p>
+    <img src="images/img1.gif" width="50" height="50"/>{" "}
+    <img src="images/img2.gif" width="50" height="50"/>
+</p>
+

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

@@ -0,0 +1,46 @@
+<div>
+    <p>Some Text</p>
+    <hr></hr>
+    Some Text&nbsp;&nbsp;
+             ~~~~~~~~~~~~ [0]
+    <select>
+    <option></option>
+    </select>
+    <button type="button">Some Text</button>
+    <button type="button">Some Text&nbsp;</button>
+                                   ~~~~~~ [0]
+    <button type="button">Some Text &nbsp; </button>
+                                    ~~~~~~ [0]
+    <button type="button">Some Text &NBSP; </button>
+    <button type="button">Some Text &nBSP; </button>
+    <br/>
+    Some Text&nbsp;
+             ~~~~~~ [0]
+    <select>
+    <option></option>
+    </select>
+    <button type="button">Some Text&nbsp;&nbsp;&nbsp;&nbsp;</button>
+                                   ~~~~~~~~~~~~~~~~~~~~~~~~ [0]
+    <button type="button">Some Text &nbsp;&nbsp;&nbsp;&nbsp; </button>
+                                    ~~~~~~~~~~~~~~~~~~~~~~~~ [0]
+    <hr></hr>
+    Some Text&nbsp;&nbsp;&nbsp;
+             ~~~~~~~~~~~~~~~~~~ [0]
+    <br/>
+    <button type="button">
+        Some Text&nbsp;
+                 ~~~~~~ [0]
+    </button>
+    <button type="button">
+        Some Text&nbsp;&nbsp;&nbsp;&nbsp;
+                 ~~~~~~~~~~~~~~~~~~~~~~~~ [0]
+    </button>
+</div>
+
+<p>
+    <img src="images/img1.gif" width="50" height="50"/>&nbsp;
+                                                       ~~~~~~ [0]
+    <img src="images/img2.gif" width="50" height="50"/>
+</p>
+
+[0]: Expected '{" "}' instead of '&nbsp;' in JSX markup

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

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