1 files changed, 120 insertions, 0 deletions
diff --git a/tools/node_modules/eslint/lib/util/fix-tracker.js b/tools/node_modules/eslint/lib/util/fix-tracker.js
new file mode 100644
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+++ b/tools/node_modules/eslint/lib/util/fix-tracker.js
@@ -0,0 +1,120 @@
+/**
+ * @fileoverview Helper class to aid in constructing fix commands.
+ * @author Alan Pierce
+ */
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const astUtils = require("../ast-utils");
+
+//------------------------------------------------------------------------------
+// Public Interface
+//------------------------------------------------------------------------------
+
+/**
+ * A helper class to combine fix options into a fix command. Currently, it
+ * exposes some "retain" methods that extend the range of the text being
+ * replaced so that other fixes won't touch that region in the same pass.
+ */
+class FixTracker {
+
+    /**
+     * Create a new FixTracker.
+     *
+     * @param {ruleFixer} fixer A ruleFixer instance.
+     * @param {SourceCode} sourceCode A SourceCode object for the current code.
+     */
+    constructor(fixer, sourceCode) {
+        this.fixer = fixer;
+        this.sourceCode = sourceCode;
+        this.retainedRange = null;
+    }
+
+    /**
+     * Mark the given range as "retained", meaning that other fixes may not
+     * may not modify this region in the same pass.
+     *
+     * @param {int[]} range The range to retain.
+     * @returns {FixTracker} The same RuleFixer, for chained calls.
+     */
+    retainRange(range) {
+        this.retainedRange = range;
+        return this;
+    }
+
+    /**
+     * Given a node, find the function containing it (or the entire program) and
+     * mark it as retained, meaning that other fixes may not modify it in this
+     * pass. This is useful for avoiding conflicts in fixes that modify control
+     * flow.
+     *
+     * @param {ASTNode} node The node to use as a starting point.
+     * @returns {FixTracker} The same RuleFixer, for chained calls.
+     */
+    retainEnclosingFunction(node) {
+        const functionNode = astUtils.getUpperFunction(node);
+
+        return this.retainRange(functionNode ? functionNode.range : this.sourceCode.ast.range);
+    }
+
+    /**
+     * Given a node or token, find the token before and afterward, and mark that
+     * range as retained, meaning that other fixes may not modify it in this
+     * pass. This is useful for avoiding conflicts in fixes that make a small
+     * change to the code where the AST should not be changed.
+     *
+     * @param {ASTNode|Token} nodeOrToken The node or token to use as a starting
+     *      point. The token to the left and right are use in the range.
+     * @returns {FixTracker} The same RuleFixer, for chained calls.
+     */
+    retainSurroundingTokens(nodeOrToken) {
+        const tokenBefore = this.sourceCode.getTokenBefore(nodeOrToken) || nodeOrToken;
+        const tokenAfter = this.sourceCode.getTokenAfter(nodeOrToken) || nodeOrToken;
+
+        return this.retainRange([tokenBefore.range[0], tokenAfter.range[1]]);
+    }
+
+    /**
+     * Create a fix command that replaces the given range with the given text,
+     * accounting for any retained ranges.
+     *
+     * @param {int[]} range The range to remove in the fix.
+     * @param {string} text The text to insert in place of the range.
+     * @returns {Object} The fix command.
+     */
+    replaceTextRange(range, text) {
+        let actualRange;
+
+        if (this.retainedRange) {
+            actualRange = [
+                Math.min(this.retainedRange[0], range[0]),
+                Math.max(this.retainedRange[1], range[1])
+            ];
+        } else {
+            actualRange = range;
+        }
+
+        return this.fixer.replaceTextRange(
+            actualRange,
+            this.sourceCode.text.slice(actualRange[0], range[0]) +
+                text +
+                this.sourceCode.text.slice(range[1], actualRange[1])
+        );
+    }
+
+    /**
+     * Create a fix command that removes the given node or token, accounting for
+     * any retained ranges.
+     *
+     * @param {ASTNode|Token} nodeOrToken The node or token to remove.
+     * @returns {Object} The fix command.
+     */
+    remove(nodeOrToken) {
+        return this.replaceTextRange(nodeOrToken.range, "");
+    }
+}
+
+module.exports = FixTracker;