feat(loader): add file system loader

loader will resolve templates from the file system

package.json

@@ -34,6 +34,7 @@
     "coveralls": "^3.0.2",
     "cz-conventional-changelog": "^2.1.0",
     "del-cli": "^1.1.0",
+    "fs-extra": "^6.0.1",
     "japa": "^1.0.6",
     "japa-cli": "^1.0.1",
     "mrm": "^1.1.1",
@@ -57,5 +58,8 @@
     "extension": [
       ".ts"
     ]
+  },
+  "dependencies": {
+    "edge-parser": "git+https://github.com/poppinss/edge-parser.git#develop"
   }
 }

src/Loader/index.ts

@@ -0,0 +1,65 @@
+/*
+* edge
+*
+* (c) Harminder Virk <virk@adonisjs.com>
+*
+* For the full copyright and license information, please view the LICENSE
+* file that was distributed with this source code.
+*/
+
+import { join } from 'path'
+import { readFileSync } from 'fs'
+
+export class Loader {
+  private mountedDirs: Map<string, string> = new Map()
+
+  /**
+   * Returns an object of mounted directories with their public
+   * names
+   */
+  public get mounted (): object {
+    return Array.from(this.mountedDirs).reduce((obj, [key, value]) => {
+      obj[key] = value
+      return obj
+    }, {})
+  }
+
+  /**
+   * Mount a directory for resolving views
+   */
+  public mount (name: string, dirPath: string): void {
+    this.mountedDirs.set(name, dirPath)
+  }
+
+  /**
+   * Remove directory from the list of directories
+   * for resolving views
+   */
+  public unmount (name: string): void {
+    this.mountedDirs.delete(name)
+  }
+
+  /**
+   * Resolves a template from disk and returns it as a string
+   */
+  public resolve (template: string, name: string = 'default'): string {
+    const mountedDir = this.mountedDirs.get(name)
+    if (!mountedDir) {
+      throw new Error(`Attempting to resolve ${template} template for unmounted ${name} location`)
+    }
+
+    /**
+     * Normalize template name by adding extension
+     */
+    template = `${template.replace(/\.edge$/, '')}.edge`
+
+    try {
+      return readFileSync(join(mountedDir, template), 'utf-8')
+    } catch (error) {
+      if (error.code === 'ENOENT') {
+        throw new Error(`Cannot resolve ${template}. Make sure file exists at ${mountedDir} location.`)
+      }
+      throw error
+    }
+  }
+}

test/loader.spec.ts

@@ -0,0 +1,70 @@
+/*
+* edge
+*
+* (c) Harminder Virk <virk@adonisjs.com>
+*
+* For the full copyright and license information, please view the LICENSE
+* file that was distributed with this source code.
+*/
+
+import * as test from 'japa'
+import * as fs from 'fs-extra'
+
+import { join } from 'path'
+import { Loader } from '../src/Loader'
+
+const viewsDir = join(__dirname, 'views')
+
+test.group('Loader', (group) => {
+  group.afterEach(async () => {
+    await fs.remove(viewsDir)
+  })
+
+  test('mount path with a name', (assert) => {
+    const loader = new Loader()
+    loader.mount('default', viewsDir)
+    assert.deepEqual(loader.mounted, { default: join(__dirname, 'views') })
+  })
+
+  test('unmount path with a name', (assert) => {
+    const loader = new Loader()
+    loader.mount('default', viewsDir)
+    loader.unmount('default')
+
+    assert.deepEqual(loader.mounted, {})
+  })
+
+  test('throw exception when resolve path from undefined location', (assert) => {
+    const loader = new Loader()
+    const fn = () => loader.resolve('foo')
+    assert.throw(fn, 'Attempting to resolve foo template for unmounted default location')
+  })
+
+  test('resolve template for given location', async (assert) => {
+    await fs.outputFile(join(viewsDir, 'foo.edge'), 'Hello world')
+
+    const loader = new Loader()
+    loader.mount('default', viewsDir)
+
+    const template = loader.resolve('foo')
+    assert.equal(template.trim(), 'Hello world')
+  })
+
+  test('raise error when template is missing', async (assert) => {
+    const loader = new Loader()
+    loader.mount('default', viewsDir)
+
+    const fn = () => loader.resolve('foo')
+    assert.throw(fn, `Cannot resolve foo.edge. Make sure file exists at ${viewsDir} location.`)
+  })
+
+  test('resolve template with extension', async (assert) => {
+    await fs.outputFile(join(viewsDir, 'foo.edge'), 'Hello world')
+
+    const loader = new Loader()
+    loader.mount('default', viewsDir)
+
+    const template = loader.resolve('foo.edge')
+    assert.equal(template.trim(), 'Hello world')
+  })
+})