1 files changed, 152 insertions, 0 deletions
diff --git a/tools/node_modules/eslint/lib/util/source-code-fixer.js b/tools/node_modules/eslint/lib/util/source-code-fixer.js
new file mode 100644
index 0000000000..b5bfc7457a
--- /dev/null
+++ b/tools/node_modules/eslint/lib/util/source-code-fixer.js
@@ -0,0 +1,152 @@
+/**
+ * @fileoverview An object that caches and applies source code fixes.
+ * @author Nicholas C. Zakas
+ */
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const debug = require("debug")("eslint:text-fixer");
+
+//------------------------------------------------------------------------------
+// Helpers
+//------------------------------------------------------------------------------
+
+const BOM = "\uFEFF";
+
+/**
+ * Compares items in a messages array by range.
+ * @param {Message} a The first message.
+ * @param {Message} b The second message.
+ * @returns {int} -1 if a comes before b, 1 if a comes after b, 0 if equal.
+ * @private
+ */
+function compareMessagesByFixRange(a, b) {
+    return a.fix.range[0] - b.fix.range[0] || a.fix.range[1] - b.fix.range[1];
+}
+
+/**
+ * Compares items in a messages array by line and column.
+ * @param {Message} a The first message.
+ * @param {Message} b The second message.
+ * @returns {int} -1 if a comes before b, 1 if a comes after b, 0 if equal.
+ * @private
+ */
+function compareMessagesByLocation(a, b) {
+    return a.line - b.line || a.column - b.column;
+}
+
+//------------------------------------------------------------------------------
+// Public Interface
+//------------------------------------------------------------------------------
+
+/**
+ * Utility for apply fixes to source code.
+ * @constructor
+ */
+function SourceCodeFixer() {
+    Object.freeze(this);
+}
+
+/**
+ * Applies the fixes specified by the messages to the given text. Tries to be
+ * smart about the fixes and won't apply fixes over the same area in the text.
+ * @param {string} sourceText The text to apply the changes to.
+ * @param {Message[]} messages The array of messages reported by ESLint.
+ * @param {boolean|Function} [shouldFix=true] Determines whether each message should be fixed
+ * @returns {Object} An object containing the fixed text and any unfixed messages.
+ */
+SourceCodeFixer.applyFixes = function(sourceText, messages, shouldFix) {
+    debug("Applying fixes");
+
+    if (shouldFix === false) {
+        debug("shouldFix parameter was false, not attempting fixes");
+        return {
+            fixed: false,
+            messages,
+            output: sourceText
+        };
+    }
+
+    // clone the array
+    const remainingMessages = [],
+        fixes = [],
+        bom = sourceText.startsWith(BOM) ? BOM : "",
+        text = bom ? sourceText.slice(1) : sourceText;
+    let lastPos = Number.NEGATIVE_INFINITY,
+        output = bom;
+
+    /**
+     * Try to use the 'fix' from a problem.
+     * @param   {Message} problem The message object to apply fixes from
+     * @returns {boolean}         Whether fix was successfully applied
+     */
+    function attemptFix(problem) {
+        const fix = problem.fix;
+        const start = fix.range[0];
+        const end = fix.range[1];
+
+        // Remain it as a problem if it's overlapped or it's a negative range
+        if (lastPos >= start || start > end) {
+            remainingMessages.push(problem);
+            return false;
+        }
+
+        // Remove BOM.
+        if ((start < 0 && end >= 0) || (start === 0 && fix.text.startsWith(BOM))) {
+            output = "";
+        }
+
+        // Make output to this fix.
+        output += text.slice(Math.max(0, lastPos), Math.max(0, start));
+        output += fix.text;
+        lastPos = end;
+        return true;
+    }
+
+    messages.forEach(problem => {
+        if (problem.hasOwnProperty("fix")) {
+            fixes.push(problem);
+        } else {
+            remainingMessages.push(problem);
+        }
+    });
+
+    if (fixes.length) {
+        debug("Found fixes to apply");
+        let fixesWereApplied = false;
+
+        for (const problem of fixes.sort(compareMessagesByFixRange)) {
+            if (typeof shouldFix !== "function" || shouldFix(problem)) {
+                attemptFix(problem);
+
+                /*
+                 * The only time attemptFix will fail is if a previous fix was
+                 * applied which conflicts with it.  So we can mark this as true.
+                 */
+                fixesWereApplied = true;
+            } else {
+                remainingMessages.push(problem);
+            }
+        }
+        output += text.slice(Math.max(0, lastPos));
+
+        return {
+            fixed: fixesWereApplied,
+            messages: remainingMessages.sort(compareMessagesByLocation),
+            output
+        };
+    }
+
+    debug("No fixes to apply");
+    return {
+        fixed: false,
+        messages,
+        output: bom + text
+    };
+
+};
+
+module.exports = SourceCodeFixer;