feat: jsxSpaceBeforeTrailingSlashRule

src/jsxSpaceBeforeTrailingSlashRule.ts

@@ -0,0 +1,41 @@
+import * as Lint from "tslint";
+import * as ts from "typescript";
+
+class JsxSpaceBeforeTrailingSlashRule extends Lint.RuleWalker {
+  private readonly enforceWhiteSpace: boolean = true;
+  constructor(
+    sourceFile: ts.SourceFile,
+    options: Lint.IOptions
+  ) {
+    super(sourceFile, options);
+    if (options.ruleArguments[0] === "never") {
+      this.enforceWhiteSpace = false;
+    }
+  }
+
+  private static hasWhitespaceBeforeClosing(nodeText: string): boolean {
+    return /\s/.test(nodeText.charAt(nodeText.length - "/>".length - 1));
+  }
+
+  public visitJsxSelfClosingElement(node: ts.JsxSelfClosingElement): void {
+    super.visitJsxSelfClosingElement(node);
+    if (this.enforceWhiteSpace) {
+      if (!JsxSpaceBeforeTrailingSlashRule.hasWhitespaceBeforeClosing(node.getText())) {
+        this.addFailureAtNode(node, "Self-closing JSX elements must have a space before the '/>' part");
+        return;
+      }
+    } else {
+      if (!/[\r\n]/.test(node.getText()) && JsxSpaceBeforeTrailingSlashRule.hasWhitespaceBeforeClosing(node.getText())) {
+        this.addFailureAtNode(node, "One-line self-closing JSX elements must not have a space(s) before the '/>' part");
+        return;
+      }
+    }
+  }
+}
+
+// tslint:disable-next-line:export-name max-classes-per-file
+export class Rule extends Lint.Rules.TypedRule {
+  public applyWithProgram(sourceFile: ts.SourceFile, program: ts.Program): Lint.RuleFailure[] {
+    return this.applyWithWalker(new JsxSpaceBeforeTrailingSlashRule(sourceFile, this.getOptions()));
+  }
+}

test/rules/jsx-space-before-trailing-slash/default/test.tsx.lint

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+<div>
+    Contents
+</div>
+
+<span/>
+~~~~~~~ [Self-closing JSX elements must have a space before the '/>' part]
+
+<button />
+
+<h2 class="colouring" contents="B"/>
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ [Self-closing JSX elements must have a space before the '/>' part]
+
+<button onClick="run()" />
+
+<img
+  src="./foo/bar.png"
+/>
+
+<div>
+  <img
+    src="./foo/bar.png"
+  />
+</div>

test/rules/jsx-space-before-trailing-slash/default/tsconfig.json

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+{
+  "compilerOptions": {
+    "module": "commonjs",
+    "target": "es5",
+    "lib": ["es6"]
+  }
+}

test/rules/jsx-space-before-trailing-slash/default/tslint.json

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+{
+  "rulesDirectory": [
+    "../../../../lib"
+  ],
+  "rules": {
+    "jsx-space-before-trailing-slash": true
+  }
+}

test/rules/jsx-space-before-trailing-slash/never/test.tsx.lint

@@ -0,0 +1,23 @@
+<div>
+    Contents
+</div>
+
+<span/>
+
+<button />
+~~~~~~~~~~ [One-line self-closing JSX elements must not have a space(s) before the '/>' part]
+
+<h2 class="colouring" contents="B"/>
+
+<button onClick="run()" />
+~~~~~~~~~~~~~~~~~~~~~~~~~~ [One-line self-closing JSX elements must not have a space(s) before the '/>' part]
+
+<img
+  src="./foo/bar.png"
+/>
+
+<div>
+  <img
+    src="./foo/bar.png"
+  />
+</div>

test/rules/jsx-space-before-trailing-slash/never/tsconfig.json

@@ -0,0 +1,7 @@
+{
+  "compilerOptions": {
+    "module": "commonjs",
+    "target": "es5",
+    "lib": ["es6"]
+  }
+}

test/rules/jsx-space-before-trailing-slash/never/tslint.json

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+{
+  "rulesDirectory": [
+    "../../../../lib"
+  ],
+  "rules": {
+    "jsx-space-before-trailing-slash": [true, "never"]
+  }
+}