Merge pull request palantir#46 from gscshoyru/no-consecutive-blank-lines

Added no-consecutive-blank-lines rule

README.md

@@ -12,13 +12,14 @@ 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' 
+* `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.
 * `no-arg` disallows access to `arguments.callee`.
 * `no-bitwise` disallows bitwise operators.
 * `no-console` disallows access to the specified functions on `console`. Rule options are functions to ban on the console variable.
+* `no-consecutive-blank-lines` disallows having more than one blank line in a row in a file
 * `no-construct` disallows access to the constructors of `String`, `Number`, and `Boolean`.
 * `no-debugger` disallows `debugger` statements.
 * `no-duplicate-key` disallows duplicate keys in object literals.

src/rules/noConsecutiveBlankLinesRule.ts

@@ -0,0 +1,55 @@
+/*
+ * 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 = "consecutive blank lines are disallowed";
+
+    public apply(syntaxTree: TypeScript.SyntaxTree): Lint.RuleFailure[] {
+        return this.applyWithWalker(new BlankLinesWalker(syntaxTree, this.getOptions()));
+    }
+}
+
+class BlankLinesWalker extends Lint.RuleWalker {
+    // starting with 1 to cover the case where the file starts with two blank lines
+    private newLinesInARowSeenSoFar = 1;
+
+    public visitToken(token: TypeScript.ISyntaxToken): void {
+        this.findConsecutiveBlankLinesFromTriva(token.leadingTrivia().toArray(), this.position());
+        this.newLinesInARowSeenSoFar = 0;
+        this.findConsecutiveBlankLinesFromTriva(token.trailingTrivia().toArray(),
+            this.position() + token.leadingTriviaWidth() + token.width());
+
+        super.visitToken(token);
+    }
+
+    private findConsecutiveBlankLinesFromTriva(triviaList: TypeScript.ISyntaxTrivia[], currentPosition: number) {
+        triviaList.forEach((triviaItem) => {
+            if (triviaItem.isNewLine()) {
+                this.newLinesInARowSeenSoFar += 1;
+                if (this.newLinesInARowSeenSoFar >= 3) {
+                    var failure = this.createFailure(currentPosition, 1, Rule.FAILURE_STRING);
+                    this.addFailure(failure);
+                }
+            } else {
+                this.newLinesInARowSeenSoFar = 0;
+            }
+            currentPosition += triviaItem.fullWidth();
+        });
+    }
+
+}

test/files/rules/blanklines.test.ts

@@ -0,0 +1,15 @@
+
+
+class Clazz { // comment
+
+    public funcxion() {
+
+        // also comment
+
+
+        console.log("test");
+
+    }
+
+
+}

test/rules/noConsecutiveBlankLinesRuleTests.ts

@@ -0,0 +1,36 @@
+/*
+ * 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("<no-consecutive-blank-lines>", () => {
+    var NoConsecutiveBlankLinesRule = Lint.Test.getRule("no-consecutive-blank-lines");
+
+    it("ensures comments start with a space and a lowercase letter", () => {
+        var fileName = "rules/blanklines.test.ts";
+        var createFailure = Lint.Test.createFailuresOnFile(fileName, NoConsecutiveBlankLinesRule.FAILURE_STRING);
+        var expectedFailure1 = createFailure([2, 1], [3, 1]);
+        var expectedFailure2 = createFailure([9, 1], [10, 1]);
+        var expectedFailure3 = createFailure([14, 1], [15, 1]);
+
+        var actualFailures = Lint.Test.applyRuleOnFile(fileName, NoConsecutiveBlankLinesRule);
+
+        Lint.Test.assertContainsFailure(actualFailures, expectedFailure1);
+        Lint.Test.assertContainsFailure(actualFailures, expectedFailure2);
+        Lint.Test.assertContainsFailure(actualFailures, expectedFailure3);
+        assert.lengthOf(actualFailures, 3);
+    });
+});