From 19f6fff6d5f9a576ac956d3aee3a5e084873398e Mon Sep 17 00:00:00 2001
From: "Nicholas C. Zakas" <nicholas@nczconsulting.com>
Date: Thu, 14 Apr 2016 14:37:09 -0700
Subject: [PATCH] Update: Autofixing does multiple passes (refs #5329)

---
 lib/cli-engine.js       | 89 +++++++++++++++++++++++++++++++++++++----
 tests/lib/cli-engine.js | 26 +++---------
 2 files changed, 87 insertions(+), 28 deletions(-)

diff --git a/lib/cli-engine.js b/lib/cli-engine.js
index 2cc62f955eac..e54bf7bf02f1 100644
--- a/lib/cli-engine.js
+++ b/lib/cli-engine.js
@@ -115,6 +115,79 @@ function calculateStatsPerRun(results) {
     });
 }
 
+/**
+ * Performs multiple autofix passes over the text until as many fixes as possible
+ * have been applied.
+ * @param {string} text The source text to apply fixes to.
+ * @param {Object} config The ESLint config object to use.
+ * @param {Object} options The ESLint options object to use.
+ * @param {string} options.filename The filename from which the text was read.
+ * @param {boolean} options.allowInlineConfig Flag indicating if inline comments
+ *      should be allowed.
+ * @returns {Object} The result of the fix operation as returned from the
+ *      SourceCodeFixer.
+ * @private
+ */
+function multipassFix(text, config, options) {
+
+    var messages = [],
+        fixedResult,
+        fixed = false,
+        passNumber = 0,
+        lastMessageCount,
+        MAX_PASSES = 10;
+
+    /**
+     * This loop continues until one of the following is true:
+     *
+     * 1. No more fixes have been applied.
+     * 2. There are no more linting errors reported.
+     * 3. The number of linting errors is no different between two passes.
+     * 4. Ten passes have been made.
+     *
+     * That means anytime a fix is successfully applied, there will be another pass.
+     * Essentially, guaranteeing a minimum of two passes.
+     */
+    do {
+        passNumber++;
+        lastMessageCount = messages.length;
+
+        debug("Linting code for " + options.filename + " (pass " + passNumber + ")");
+        messages = eslint.verify(text, config, options);
+
+        debug("Generating fixed text for " + options.filename + " (pass " + passNumber + ")");
+        fixedResult = SourceCodeFixer.applyFixes(eslint.getSourceCode(), messages);
+
+        // keep track if any fixes were ever applied - important for return value
+        fixed = fixed || fixedResult.fixed;
+
+        // update to use the fixed output instead of the original text
+        text = fixedResult.output;
+
+    } while (
+        fixedResult.fixed && fixedResult.messages.length > 0 &&
+        fixedResult.messages.length !== lastMessageCount &&
+        passNumber < MAX_PASSES
+    );
+
+
+    /*
+     * If the last result had fixes, we need to lint again to me sure we have
+     * the most up-to-date information.
+     */
+    if (fixedResult.fixed) {
+        fixedResult.messages = eslint.verify(text, config, options);
+    }
+
+
+    // ensure the last result properly reflects if fixes were done
+    fixedResult.fixed = fixed;
+    fixedResult.output = text;
+
+    return fixedResult;
+
+}
+
 /**
  * Processes an source code using ESLint.
  * @param {string} text The source code to check.
@@ -179,15 +252,17 @@ function processText(text, configHelper, filename, fix, allowInlineConfig) {
 
     } else {
 
-        messages = eslint.verify(text, config, {
-            filename: filename,
-            allowInlineConfig: allowInlineConfig
-        });
-
         if (fix) {
-            debug("Generating fixed text for " + filename);
-            fixedResult = SourceCodeFixer.applyFixes(eslint.getSourceCode(), messages);
+            fixedResult = multipassFix(text, config, {
+                filename: filename,
+                allowInlineConfig: allowInlineConfig
+            });
             messages = fixedResult.messages;
+        } else {
+            messages = eslint.verify(text, config, {
+                filename: filename,
+                allowInlineConfig: allowInlineConfig
+            });
         }
     }
 
diff --git a/tests/lib/cli-engine.js b/tests/lib/cli-engine.js
index 967d93e53da0..f2a59b186a8b 100644
--- a/tests/lib/cli-engine.js
+++ b/tests/lib/cli-engine.js
@@ -914,22 +914,6 @@ describe("CLIEngine", function() {
                         {
                             "filePath": fs.realpathSync(path.resolve(fixtureDir, "fixmode/quotes-semi-eqeqeq.js")),
                             "messages": [
-                                {
-                                    "column": 11,
-                                    "fix": {
-                                        "range": [
-                                            10,
-                                            14
-                                        ],
-                                        "text": "\"hi\""
-                                    },
-                                    "line": 1,
-                                    "message": "Strings must use doublequote.",
-                                    "nodeType": "Literal",
-                                    "ruleId": "quotes",
-                                    "severity": 2,
-                                    "source": "var msg = 'hi'"
-                                },
                                 {
                                     "column": 9,
                                     "line": 2,
@@ -937,12 +921,12 @@ describe("CLIEngine", function() {
                                     "nodeType": "BinaryExpression",
                                     "ruleId": "eqeqeq",
                                     "severity": 2,
-                                    "source": "if (msg == 'hi') {"
+                                    "source": "if (msg == \"hi\") {"
                                 }
                             ],
-                            "errorCount": 2,
+                            "errorCount": 1,
                             "warningCount": 0,
-                            "output": "var msg = 'hi';\nif (msg == \"hi\") {\n\n}\n"
+                            "output": "var msg = \"hi\";\nif (msg == \"hi\") {\n\n}\n"
                         },
                         {
                             "filePath": fs.realpathSync(path.resolve(fixtureDir, "fixmode/quotes.js")),
@@ -954,7 +938,7 @@ describe("CLIEngine", function() {
                                     nodeType: "Identifier",
                                     ruleId: "no-undef",
                                     severity: 2,
-                                    source: "var msg = 'hi' + foo;"
+                                    source: "var msg = \"hi\" + foo;"
                                 }
                             ],
                             "errorCount": 1,
@@ -962,7 +946,7 @@ describe("CLIEngine", function() {
                             "output": "var msg = \"hi\" + foo;\n"
                         }
                     ],
-                    "errorCount": 3,
+                    "errorCount": 2,
                     "warningCount": 0
                 });
             });