Merge pull request palantir#43 from gscshoyru/interface-name-branch

Added interface-name rule

README.md

@@ -11,6 +11,7 @@ Supported Rules
 * `eofline` enforces the file to end with a newline.
 * `forin` enforces a `for ... in` statement to be filtered with an `if` statement.*
 * `indent` enforces consistent indentation levels (currently disabled).
+* `interface-name` enforces the rule that interface names must begin with a capital 'I' 
 * `label-position` enforces labels only on sensible statements.
 * `label-undefined` checks that labels are defined before usage.
 * `max-line-length` sets the maximum length of a line.

src/rules/interfaceNameRule.ts

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2013 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.
+*/
+
+/// <reference path='../../lib/tslint.d.ts' />
+
+export class Rule extends Lint.Rules.AbstractRule {
+    static FAILURE_STRING = "interface name must start with capital I";
+
+    public apply(syntaxTree: TypeScript.SyntaxTree): Lint.RuleFailure[] {
+        return this.applyWithWalker(new NameWalker(syntaxTree));
+    }
+}
+
+class NameWalker extends Lint.RuleWalker {
+    public visitInterfaceDeclaration(node: TypeScript.InterfaceDeclarationSyntax): void {
+        var interfaceName = node.identifier.text();
+        if (!this.startsWithI(interfaceName)) {
+            var position = this.positionAfter(node.modifiers, node.interfaceKeyword);
+            this.addFailureAt(position, node.identifier.width());
+        }
+
+        super.visitInterfaceDeclaration(node);
+    }
+
+    private startsWithI(name): boolean {
+        if (name.length <= 0) {
+            return true;
+        }
+
+        var firstCharacter = name.charAt(0);
+        return (firstCharacter === "I");
+    }
+
+    private addFailureAt(position, width) {
+        var failure = this.createFailure(position, width, Rule.FAILURE_STRING);
+        this.addFailure(failure);
+    }
+
+}

test/files/rules/interfacename.test.ts

@@ -0,0 +1,7 @@
+interface IValidInterfaceName {
+
+}
+
+interface NotValidInterfaceName {
+
+}

test/rules/interfaceNameRuleTests.ts

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2013 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.
+*/
+
+/// <reference path='../references.ts' />
+
+describe("<interface-name>", () => {
+    var InterfaceNameRule = Lint.Test.getRule("interface-name");
+
+    it("ensures interface names always start with a capital I", () => {
+        var fileName = "rules/interfacename.test.ts";
+        var createFailure = Lint.Test.createFailuresOnFile(fileName, InterfaceNameRule.FAILURE_STRING);
+        var expectedFailure1 = createFailure([5, 11], [5, 32]);
+        var actualFailures = Lint.Test.applyRuleOnFile(fileName, InterfaceNameRule);
+
+        Lint.Test.assertContainsFailure(actualFailures, expectedFailure1);
+    });
+});