Add editor config utils

lib/utils/editorconfig.js

@@ -0,0 +1,17 @@
+'use strict';
+
+const editorconfig = require('editorconfig');
+
+/**
+ * Resolve editorconfig properties for a given file path using the official
+ * editorconfig library.
+ *
+ * Returns an object like `{ indent_size: 4, indent_style: 'space', ... }`
+ * with only the properties that matched. Returns an empty object if no
+ * .editorconfig is found or no sections match.
+ */
+function resolveEditorConfig(filePath) {
+  return editorconfig.parseSync(filePath);
+}
+
+module.exports = { resolveEditorConfig };

package.json

@@ -61,6 +61,7 @@
   "dependencies": {
     "@ember-data/rfc395-data": "^0.0.4",
     "css-tree": "^3.0.1",
+    "editorconfig": "^3.0.2",
     "ember-eslint-parser": "^0.6.0",
     "ember-rfc176-data": "^0.3.18",
     "eslint-utils": "^3.0.0",

tests/lib/utils/editorconfig-test.js

@@ -0,0 +1,110 @@
+'use strict';
+
+const fs = require('fs');
+const path = require('path');
+const os = require('os');
+const { resolveEditorConfig } = require('../../../lib/utils/editorconfig');
+
+describe('resolveEditorConfig', () => {
+  let tmpDir;
+
+  beforeEach(() => {
+    tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'editorconfig-test-'));
+  });
+
+  afterEach(() => {
+    fs.rmSync(tmpDir, { recursive: true, force: true });
+  });
+
+  it('returns empty object when no .editorconfig exists', () => {
+    const filePath = path.join(tmpDir, 'test.hbs');
+    const result = resolveEditorConfig(filePath);
+    expect(result).toEqual({});
+  });
+
+  it('reads indent_size from .editorconfig', () => {
+    fs.writeFileSync(
+      path.join(tmpDir, '.editorconfig'),
+      ['root = true', '', '[*]', 'indent_size = 4'].join('\n')
+    );
+    const filePath = path.join(tmpDir, 'test.hbs');
+    const result = resolveEditorConfig(filePath);
+    expect(result.indent_size).toBe(4);
+  });
+
+  it('matches *.hbs sections', () => {
+    fs.writeFileSync(
+      path.join(tmpDir, '.editorconfig'),
+      ['root = true', '', '[*.hbs]', 'indent_size = 3'].join('\n')
+    );
+    const filePath = path.join(tmpDir, 'test.hbs');
+    const result = resolveEditorConfig(filePath);
+    expect(result.indent_size).toBe(3);
+  });
+
+  it('does not match non-matching glob', () => {
+    fs.writeFileSync(
+      path.join(tmpDir, '.editorconfig'),
+      ['root = true', '', '[*.js]', 'indent_size = 4'].join('\n')
+    );
+    const filePath = path.join(tmpDir, 'test.hbs');
+    const result = resolveEditorConfig(filePath);
+    expect(result.indent_size).toBeUndefined();
+  });
+
+  it('handles brace expansion *.{hbs,gjs}', () => {
+    fs.writeFileSync(
+      path.join(tmpDir, '.editorconfig'),
+      ['root = true', '', '[*.{hbs,gjs}]', 'indent_size = 6'].join('\n')
+    );
+    expect(resolveEditorConfig(path.join(tmpDir, 'test.hbs')).indent_size).toBe(6);
+    expect(resolveEditorConfig(path.join(tmpDir, 'test.gjs')).indent_size).toBe(6);
+    expect(resolveEditorConfig(path.join(tmpDir, 'test.js')).indent_size).toBeUndefined();
+  });
+
+  it('later sections override earlier ones', () => {
+    fs.writeFileSync(
+      path.join(tmpDir, '.editorconfig'),
+      ['root = true', '', '[*]', 'indent_size = 2', '', '[*.hbs]', 'indent_size = 4'].join('\n')
+    );
+    const filePath = path.join(tmpDir, 'test.hbs');
+    const result = resolveEditorConfig(filePath);
+    expect(result.indent_size).toBe(4);
+  });
+
+  it('inner .editorconfig overrides outer', () => {
+    // outer
+    fs.writeFileSync(
+      path.join(tmpDir, '.editorconfig'),
+      ['root = true', '', '[*]', 'indent_size = 2'].join('\n')
+    );
+    // inner dir
+    const innerDir = path.join(tmpDir, 'app');
+    fs.mkdirSync(innerDir);
+    fs.writeFileSync(path.join(innerDir, '.editorconfig'), ['[*]', 'indent_size = 4'].join('\n'));
+    const filePath = path.join(innerDir, 'test.hbs');
+    const result = resolveEditorConfig(filePath);
+    expect(result.indent_size).toBe(4);
+  });
+
+  it('sets indent_size to tab when indent_style is tab and indent_size unset', () => {
+    fs.writeFileSync(
+      path.join(tmpDir, '.editorconfig'),
+      ['root = true', '', '[*]', 'indent_style = tab'].join('\n')
+    );
+    const filePath = path.join(tmpDir, 'test.hbs');
+    const result = resolveEditorConfig(filePath);
+    expect(result.indent_style).toBe('tab');
+    expect(result.indent_size).toBe('tab');
+  });
+
+  it('ignores comments', () => {
+    fs.writeFileSync(
+      path.join(tmpDir, '.editorconfig'),
+      ['root = true', '# a comment', '; another comment', '[*]', 'indent_size = 5'].join('\n')
+    );
+    const filePath = path.join(tmpDir, 'test.hbs');
+    const result = resolveEditorConfig(filePath);
+    expect(result.indent_size).toBe(5);
+  });
+});