New: Visual Studio compatible formatter (fixes eslint#4708)

docs/user-guide/command-line-interface.md

@@ -285,6 +285,7 @@ This option specifies the output format for the console. Possible formats are:
 * [junit](formatters/#junit)
 * [tap](formatters/#tap)
 * [unix](formatters/#unix)
+* [visualstudio](formatters/#visualstudio)
 
 Example:
 

lib/formatters/visualstudio.js

@@ -0,0 +1,59 @@
+/**
+ * @fileoverview VisualStudio reporter
+ * @author Ronald Pijnacker
+ */
+"use strict";
+
+//------------------------------------------------------------------------------
+// Helper Functions
+//------------------------------------------------------------------------------
+
+/**
+ * Returns the severity of warning or error
+ * @param {object} message message object to examine
+ * @returns {string} severity level
+ * @private
+ */
+function getMessageType(message) {
+    if (message.fatal || message.severity === 2) {
+        return "[Error]  ";
+    } else {
+        return "[Warning]";
+    }
+}
+
+
+//------------------------------------------------------------------------------
+// Public Interface
+//------------------------------------------------------------------------------
+
+module.exports = function(results) {
+
+    var output = "",
+        total = 0;
+
+    results.forEach(function(result) {
+
+        var messages = result.messages;
+        total += messages.length;
+
+        messages.forEach(function(message) {
+
+            output += result.filePath;
+            output += "(" + (message.line || 0);
+            output += "," + (message.column || 0);
+            output += "):\t" + getMessageType(message);
+            output += " " + message.message;
+            output += message.ruleId ? "\t(" + message.ruleId + ")" : "";
+            output += "\n";
+
+        });
+
+    });
+
+    if (total > 0) {
+        output += "\n" + total + " problem" + (total !== 1 ? "s" : "");
+    }
+
+    return output;
+};

tests/lib/formatters/visualstudio.js

@@ -0,0 +1,139 @@
+/**
+ * @fileoverview Tests for VisualStudio format.
+ * @author Ronald Pijnacker
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+var assert = require("chai").assert,
+    formatter = require("../../../lib/formatters/visualstudio");
+
+//------------------------------------------------------------------------------
+// Tests
+//------------------------------------------------------------------------------
+
+describe("formatter:visualstudio", function() {
+    describe("when passed no messages", function() {
+        var code = [{
+            filePath: "foo.js",
+            messages: []
+        }];
+
+        it("should return nothing", function() {
+            var result = formatter(code);
+            assert.equal(result, "");
+        });
+    });
+
+    describe("when passed a single message", function() {
+        var code = [{
+            filePath: "foo.js",
+            messages: [{
+                message: "Unexpected foo.",
+                severity: 2,
+                line: 5,
+                column: 10,
+                ruleId: "foo"
+            }]
+        }];
+
+        it("should return a string in the format filename(x,y):\t[Error]   z for errors", function() {
+            var result = formatter(code);
+            assert.equal(result, "foo.js(5,10):\t[Error]   Unexpected foo.\t(foo)\n\n1 problem");
+        });
+
+        it("should return a string in the format filename(x,y):\t[Warning] z for warnings", function() {
+            code[0].messages[0].severity = 1;
+            var result = formatter(code);
+            assert.equal(result, "foo.js(5,10):\t[Warning] Unexpected foo.\t(foo)\n\n1 problem");
+        });
+    });
+
+    describe("when passed a fatal error message", function() {
+        var code = [{
+            filePath: "foo.js",
+            messages: [{
+                fatal: true,
+                message: "Unexpected foo.",
+                line: 5,
+                column: 10,
+                ruleId: "foo"
+            }]
+        }];
+
+        it("should return a string in the format filename(x,y):\t[Error]   z", function() {
+            var result = formatter(code);
+            assert.equal(result, "foo.js(5,10):\t[Error]   Unexpected foo.\t(foo)\n\n1 problem");
+        });
+    });
+
+    describe("when passed multiple messages", function() {
+        var code = [{
+            filePath: "foo.js",
+            messages: [{
+                message: "Unexpected foo.",
+                severity: 2,
+                line: 5,
+                column: 10,
+                ruleId: "foo"
+            }, {
+                message: "Unexpected bar.",
+                severity: 1,
+                line: 6,
+                column: 11,
+                ruleId: "bar"
+            }]
+        }];
+
+        it("should return a string with multiple entries", function() {
+            var result = formatter(code);
+            assert.equal(result, "foo.js(5,10):\t[Error]   Unexpected foo.\t(foo)\nfoo.js(6,11):\t[Warning] Unexpected bar.\t(bar)\n\n2 problems");
+        });
+    });
+
+    describe("when passed multiple files with 1 message each", function() {
+        var code = [{
+            filePath: "foo.js",
+            messages: [{
+                message: "Unexpected foo.",
+                severity: 2,
+                line: 5,
+                column: 10,
+                ruleId: "foo"
+            }]
+        }, {
+            filePath: "bar.js",
+            messages: [{
+                message: "Unexpected bar.",
+                severity: 1,
+                line: 6,
+                column: 11,
+                ruleId: "bar"
+            }]
+        }];
+
+        it("should return a string with multiple entries", function() {
+            var result = formatter(code);
+            assert.equal(result, "foo.js(5,10):\t[Error]   Unexpected foo.\t(foo)\nbar.js(6,11):\t[Warning] Unexpected bar.\t(bar)\n\n2 problems");
+        });
+    });
+
+    describe("when passed one file not found message", function() {
+        var code = [{
+            filePath: "foo.js",
+            messages: [{
+                fatal: true,
+                message: "Couldn't find foo.js."
+            }]
+        }];
+
+        it("should return a string without line and column", function() {
+            var result = formatter(code);
+            assert.equal(result, "foo.js(0,0):\t[Error]   Couldn't find foo.js.\n\n1 problem");
+        });
+    });
+});