Prefer pipenv on project when possible

Author: just-paja

lib/main.js

@@ -9,6 +9,8 @@
 import { CompositeDisposable } from 'atom';
 import path from 'path';
 
+import { loadProjectConfig } from './pipenv';
+
 const lazyReq = require('lazy-req')(require);
 
 const { delimiter, dirname } = lazyReq('path')('delimiter', 'dirname');
@@ -111,8 +113,9 @@ export default {
         const fileDir = dirname(filePath);
         const fileText = editor.getText();
         const projectDir = getProjectDir(filePath);
+        const pipEnvConfig = await loadProjectConfig(projectDir);
         const cwd = fixPathString(this.workingDirectory, fileDir, projectDir);
-        const execPath = fixPathString(this.executablePath, '', projectDir);
+        const execPath = pipEnvConfig.pylintExecutable || fixPathString(this.executablePath, '', projectDir);
         let format = this.messageFormat;
         const patterns = {
           '%m': 'msg',
@@ -124,10 +127,10 @@ export default {
         });
         const env = Object.create(process.env, {
           PYTHONPATH: {
-            value: [
+            value: pipEnvConfig.pythonPath.concat([
               process.env.PYTHONPATH,
               fixPathString(this.pythonPath, fileDir, projectDir),
-            ].filter(x => !!x).join(delimiter),
+            ]).filter(x => !!x).join(delimiter),
             enumerable: true,
           },
           LANG: { value: 'en_US.UTF-8', enumerable: true },

lib/pipenv.js

@@ -0,0 +1,87 @@
+'use babel';
+
+import { promisify } from 'util';
+import { stat } from 'fs';
+
+const lazyReq = require('lazy-req')(require);
+
+const { exec } = lazyReq('atom-linter')('exec');
+
+import path from 'path';
+
+let pipEnvAvailable = null;
+let pipEnvProjects = {};
+
+const isPipEnvAvailable = async () => {
+  if (pipEnvAvailable !== null) {
+    return pipEnvAvailable;
+  }
+  pipEnvAvailable = await checkPipEnvAvailable();
+  return pipEnvAvailable;
+};
+
+const checkPipEnvAvailable = async () => {
+  try {
+    await exec('pipenv', ['--version']);
+    return true;
+  } catch (e) {
+    return false;
+  }
+};
+
+const getPipEnvProject = projectDir => pipEnvProjects[projectDir] || null;
+
+const readPipEnvVariable = async (lambda, defaultValue = null) => {
+  try {
+    return await lambda();
+  } catch(error) {
+    return defaultValue;
+  }
+};
+
+const loadProjectConfig = async (projectDir) => {
+  const existingConfig = getPipEnvProject(projectDir);
+  if (existingConfig) {
+    return existingConfig;
+  }
+
+  const config = {
+    pylintExecutable: null,
+    pythonPath: [],
+    pipEnvHome: null,
+  };
+
+  if (!(await isPipEnvAvailable())) {
+    pipEnvProjects[projectDir] = config;
+    return config;
+  }
+
+  config.pipEnvHome = await readPipEnvVariable(async () => await exec('pipenv', ['--venv'], {
+    cwd: projectDir,
+  }));
+  config.pythonPath = await readPipEnvVariable(async () => {
+    const pipEnvArgs = [
+      'run',
+      'python',
+      '-c',
+      'import sys; import json; print(json.dumps(sys.path))'
+    ];
+    return JSON.parse(await exec('pipenv', pipEnvArgs, {
+      cwd: projectDir,
+    }));
+  }, []);
+  config.pylintExecutable = config.pipEnvHome
+    ? await readPipEnvVariable(async () => {
+      const path = path.join(config.pipEnvHome, 'bin', 'pylint');
+      const stat = await promisify(stat)(path);
+      return stat ? path : null;
+    })
+    : null;
+  pipEnvProjects[projectDir] = config;
+  return config;
+};
+
+module.exports = {
+  loadProjectConfig,
+  getPipEnvProject,
+};