(feature): FixFormatter: new formatter for printing fixed files

src/formatters/fixFormatter.ts

@@ -0,0 +1,72 @@
+/**
+ * @license
+ * Copyright 2017 Palantir Technologies, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import * as fs from "fs";
+import {AbstractFormatter} from "../language/formatter/abstractFormatter";
+import {IFormatterMetadata} from "../language/formatter/formatter";
+import {dedent} from "../utils";
+import {Fix, RuleFailure} from "./../language/rule/rule";
+
+export class Formatter extends AbstractFormatter {
+    /* tslint:disable:object-literal-sort-keys */
+    public static metadata: IFormatterMetadata = {
+        formatterName: "fix",
+        description: "Formats the file passed in returns the formatted source",
+        sample: dedent`
+        export class FormattedClass {
+            public someMethod() {
+                return "This class has been formatted";
+            }
+        }`,
+        consumer: "machine",
+    };
+    /* tslint:enable:object-literal-sort-keys */
+
+    public format(failures: RuleFailure[]): string {
+        this.ensureExactlyOneFileInFailuresList(failures);
+
+        const fileName = failures[0].getFileName();
+        const fixes = failures.map((f) => f.getFix()).filter((f): f is Fix => !!f) as Fix[];
+        const source = fs.readFileSync(fileName, { encoding: "utf-8" });
+
+        return Fix.applyAll(source, fixes);
+    }
+
+    public ensureExactlyOneFileInFailuresList(failures: RuleFailure[]) {
+        const visitedCache: { [fileName: string]: true } = {};
+
+        for (const failure of failures) {
+            const fileName = failure.getFileName();
+
+            if (!(fileName in visitedCache)) {
+                visitedCache[fileName] = true;
+            }
+
+            if (Object.keys(visitedCache).length > 1) {
+                const files = Object.keys(visitedCache);
+                const filesFormattedForMsg = files.map((name) => `\t- ${name}`).join("\n");
+                const msg = "Only one file can be formatted with the fix formatter. \n\n" +
+                            `Attempted to format files:\n ${filesFormattedForMsg}`;
+                throw new Error(msg);
+            }
+        }
+
+        if (Object.keys(visitedCache).length !== 1) {
+            throw new Error("Must have exactly one file with failures to apply Fix formatter.");
+        }
+    }
+}

src/formatters/index.ts

@@ -22,3 +22,4 @@ export { Formatter as VerboseFormatter } from "./verboseFormatter";
 export { Formatter as StylishFormatter } from "./stylishFormatter";
 export { Formatter as FileslistFormatter } from "./fileslistFormatter";
 export { Formatter as CodeFrameFormatter } from "./codeFrameFormatter";
+export { Formatter as FixFormatter } from "./fixFormatter";

test/files/formatters/fixFormatter.test.ts

@@ -0,0 +1 @@
+var x = 123;

test/formatters/fixFormatterTests.ts

@@ -0,0 +1,86 @@
+/**
+ * @license
+ * Copyright 2017 Palantir Technologies, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import * as path from "path";
+import * as ts from "typescript";
+
+import {Fix, IFormatter, Replacement, RuleFailure, TestUtils} from "../lint";
+
+describe("Fix Formatter", () => {
+    let sourceFile: ts.SourceFile;
+    let formatter: IFormatter;
+
+    before(() => {
+        const Formatter = TestUtils.getFormatter("fix");
+        const sourceFilePath = path.resolve(__dirname, "../../../test/files/formatters/fixFormatter.test.ts");
+        sourceFile = TestUtils.getSourceFileAbsolute(sourceFilePath);
+        formatter = new Formatter();
+    });
+
+    it("returns the formatted source", () => {
+        const failures = [
+            new RuleFailure(
+                sourceFile,
+                0,
+                3,
+                "",
+                "no-var-keyword",
+                new Fix("no-var-keyword", [new Replacement(0, 3, "let")]),
+            ),
+        ];
+
+        const actualResult = formatter.format(failures);
+        assert.deepEqual(actualResult, "let x = 123;\n");
+    });
+
+    it("fails when there are multiple files given", () => {
+        const failures = [
+            new RuleFailure(
+                sourceFile,
+                0,
+                3,
+                "",
+                "no-var-keyword",
+                new Fix("no-var-keyword", [new Replacement(0, 3, "let")]),
+            ),
+            new RuleFailure(
+                TestUtils.getSourceFile("formatters/jsonFormatter.test.ts"),
+                0,
+                3,
+                "",
+                "no-var-keyword",
+                new Fix("no-var-keyword", [new Replacement(0, 3, "let")]),
+            ),
+        ];
+
+        try {
+            formatter.format(failures);
+            throw new Error("Should not happen");
+        } catch (e) {
+            assert.include(e.message, "Only one file can be formatted with the fix formatter.");
+        }
+    });
+
+    it("throws an an error when there are no failures", () => {
+        try {
+            formatter.format([]);
+            throw new Error("Should not happen");
+        } catch (e) {
+            assert.deepEqual("Must have exactly one file with failures to apply Fix formatter.", e.message);
+        }
+    });
+});

test/utils.ts

@@ -28,6 +28,12 @@ export function getSourceFile(fileName: string): ts.SourceFile {
     return Lint.getSourceFile(fileName, source);
 }
 
+export function getSourceFileAbsolute(fileName: string): ts.SourceFile {
+    const source = fs.readFileSync(fileName, "utf8");
+
+    return Lint.getSourceFile(fileName, source);
+}
+
 export function getRule(ruleName: string) {
     const rulesDirectory = path.join(path.dirname(module.filename), "../src/rules");
     return Lint.findRule(ruleName, rulesDirectory);