1 files changed, 83 insertions, 0 deletions
diff --git a/tools/node_modules/eslint/lib/rules/no-lonely-if.js b/tools/node_modules/eslint/lib/rules/no-lonely-if.js
new file mode 100644
index 0000000000..db127d1945
--- /dev/null
+++ b/tools/node_modules/eslint/lib/rules/no-lonely-if.js
@@ -0,0 +1,83 @@
+/**
+ * @fileoverview Rule to disallow if as the only statmenet in an else block
+ * @author Brandon Mills
+ */
+"use strict";
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+module.exports = {
+    meta: {
+        docs: {
+            description: "disallow `if` statements as the only statement in `else` blocks",
+            category: "Stylistic Issues",
+            recommended: false
+        },
+
+        schema: [],
+
+        fixable: "code"
+    },
+
+    create(context) {
+        const sourceCode = context.getSourceCode();
+
+        return {
+            IfStatement(node) {
+                const ancestors = context.getAncestors(),
+                    parent = ancestors.pop(),
+                    grandparent = ancestors.pop();
+
+                if (parent && parent.type === "BlockStatement" &&
+                        parent.body.length === 1 && grandparent &&
+                        grandparent.type === "IfStatement" &&
+                        parent === grandparent.alternate) {
+                    context.report({
+                        node,
+                        message: "Unexpected if as the only statement in an else block.",
+                        fix(fixer) {
+                            const openingElseCurly = sourceCode.getFirstToken(parent);
+                            const closingElseCurly = sourceCode.getLastToken(parent);
+                            const elseKeyword = sourceCode.getTokenBefore(openingElseCurly);
+                            const tokenAfterElseBlock = sourceCode.getTokenAfter(closingElseCurly);
+                            const lastIfToken = sourceCode.getLastToken(node.consequent);
+                            const sourceText = sourceCode.getText();
+
+                            if (sourceText.slice(openingElseCurly.range[1],
+                                node.range[0]).trim() || sourceText.slice(node.range[1], closingElseCurly.range[0]).trim()) {
+
+                                // Don't fix if there are any non-whitespace characters interfering (e.g. comments)
+                                return null;
+                            }
+
+                            if (
+                                node.consequent.type !== "BlockStatement" && lastIfToken.value !== ";" && tokenAfterElseBlock &&
+                                (
+                                    node.consequent.loc.end.line === tokenAfterElseBlock.loc.start.line ||
+                                    /^[([/+`-]/.test(tokenAfterElseBlock.value) ||
+                                    lastIfToken.value === "++" ||
+                                    lastIfToken.value === "--"
+                                )
+                            ) {
+
+                                /*
+                                 * If the `if` statement has no block, and is not followed by a semicolon, make sure that fixing
+                                 * the issue would not change semantics due to ASI. If this would happen, don't do a fix.
+                                 */
+                                return null;
+                            }
+
+                            return fixer.replaceTextRange(
+                                [openingElseCurly.range[0], closingElseCurly.range[1]],
+                                (elseKeyword.range[1] === openingElseCurly.range[0] ? " " : "") + sourceCode.getText(node)
+                            );
+                        }
+                    });
+                }
+            }
+        };
+
+    }
+};