Handle multiple versions of Flake8

Check which version of Flake8 is running before using version dependent commands.

lib/main.js

@@ -5,9 +5,11 @@ import { CompositeDisposable } from 'atom';
 import fs from 'fs-plus';
 import path from 'path';
 import * as helpers from 'atom-linter';
+import semver from 'semver';
 
 // Local variables
 const parseRegex = /(\d+):(\d+):\s(([A-Z])\d{2,3})\s+(.*)/g;
+const execPathVersions = new Map();
 
 const applySubstitutions = (givenExecPath, projDir) => {
   let execPath = givenExecPath;
@@ -73,6 +75,22 @@ const generateInvalidPointTrace = async (execPath, match, filePath, textEditor,
   };
 };
 
+const determineExecVersion = async (execPath) => {
+  const versionString = await helpers.exec(execPath, ['--version'], { ignoreExitCode: true });
+  const versionPattern = /^[^\s]+/g;
+  const match = versionString.match(versionPattern);
+  if (match !== null) {
+    execPathVersions.set(execPath, match[0]);
+  }
+}
+
+const getFlake8Version = async (execPath) => {
+  if (!execPathVersions.has(execPath)) {
+    await determineExecVersion(execPath);
+  }
+  return execPathVersions.get(execPath);
+}
+
 export default {
   activate() {
     this.idleCallbacks = new Set();
@@ -150,6 +168,15 @@ export default {
         const projectPath = atom.project.relativizePath(filePath)[0];
         const baseDir = projectPath !== null ? projectPath : path.dirname(filePath);
         const configFilePath = await helpers.findCachedAsync(baseDir, this.projectConfigFile);
+        const execPath = fs.normalize(applySubstitutions(this.executablePath, baseDir));
+
+        // get the version of Flake8
+        const version = await getFlake8Version(execPath);
+
+        // stdin-display-name available since 3.0.0
+        if (semver.valid(version) && semver.gte(version, '3.0.0')) {
+          parameters.push('--stdin-display-name', filePath);
+        }
 
         if (this.projectConfigFile && baseDir !== null && configFilePath !== null) {
           parameters.push('--config', configFilePath);
@@ -173,11 +200,9 @@ export default {
             parameters.push('--builtins', this.builtins.join(','));
           }
         }
-        parameters.push('--stdin-display-name', filePath);
 
         parameters.push('-');
 
-        const execPath = fs.normalize(applySubstitutions(this.executablePath, baseDir));
         const forceTimeout = 1000 * 60 * 5; // (ms * s * m) = Five minutes
         const options = {
           stdin: fileText,

package.json

@@ -85,7 +85,8 @@
   "dependencies": {
     "atom-linter": "^10.0.0",
     "atom-package-deps": "^4.0.1",
-    "fs-plus": "^3.0.0"
+    "fs-plus": "^3.0.0",
+    "semver": "^5.4.1"
   },
   "devDependencies": {
     "eslint": "^4.3.0",