1 files changed, 85 insertions, 0 deletions
diff --git a/tools/eslint/lib/rules/space-before-blocks.js b/tools/eslint/lib/rules/space-before-blocks.js
new file mode 100644
index 0000000000..963ff42598
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+++ b/tools/eslint/lib/rules/space-before-blocks.js
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+/**
+ * @fileoverview A rule to ensure whitespace before blocks.
+ * @author Mathias Schreck <https://github.com/lo1tuma>
+ * @copyright 2014 Mathias Schreck. All rights reserved.
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+module.exports = function (context) {
+    var requireSpace = context.options[0] !== "never";
+
+    /**
+     * Determines whether two adjacent tokens are have whitespace between them.
+     * @param {Object} left - The left token object.
+     * @param {Object} right - The right token object.
+     * @returns {boolean} Whether or not there is space between the tokens.
+     */
+    function isSpaced(left, right) {
+        return left.range[1] < right.range[0];
+    }
+
+    /**
+     * Determines whether two adjacent tokens are on the same line.
+     * @param {Object} left - The left token object.
+     * @param {Object} right - The right token object.
+     * @returns {boolean} Whether or not the tokens are on the same line.
+     */
+    function isSameLine(left, right) {
+        return left.loc.start.line === right.loc.start.line;
+    }
+
+    /**
+     * Checks the given BlockStatement node has a preceding space if it doesn’t start on a new line.
+     * @param {ASTNode|Token} node The AST node of a BlockStatement.
+     * @returns {void} undefined.
+     */
+    function checkPrecedingSpace(node) {
+        var precedingToken = context.getTokenBefore(node),
+            hasSpace;
+
+        if (precedingToken && isSameLine(precedingToken, node)) {
+            hasSpace = isSpaced(precedingToken, node);
+
+            if (requireSpace) {
+                if (!hasSpace) {
+                    context.report(node, "Missing space before opening brace.");
+                }
+            } else {
+                if (hasSpace) {
+                    context.report(node, "Unexpected space before opening brace.");
+                }
+            }
+        }
+    }
+
+    /**
+     * Checks if the CaseBlock of an given SwitchStatement node has a preceding space.
+     * @param {ASTNode} node The node of a SwitchStatement.
+     * @returns {void} undefined.
+     */
+    function checkSpaceBeforeCaseBlock(node) {
+        var cases = node.cases,
+            firstCase,
+            openingBrace;
+
+        if (cases.length > 0) {
+            firstCase = cases[0];
+            openingBrace = context.getTokenBefore(firstCase);
+        } else {
+            openingBrace = context.getLastToken(node, 1);
+        }
+
+        checkPrecedingSpace(openingBrace);
+    }
+
+    return {
+        "BlockStatement": checkPrecedingSpace,
+        "SwitchStatement": checkSpaceBeforeCaseBlock
+    };
+
+};