chore: add support for prefix and suffix with enhanced API

addons/api/addon/adapters/application.js

@@ -1,4 +1,5 @@
 import RESTAdapter from '@ember-data/adapter/rest';
+import AdapterBuildURLMixin from '../mixins/adapter-build-url';
 import config from 'ember-get-config';
 import { get } from '@ember/object';
 import { InvalidError } from '@ember-data/adapter/error';
@@ -36,7 +37,9 @@ function prenormalizeArrayResponse(response) {
   return payloadIsBlank(response) ? {items: []} : response;
 }
 
-export default class ApplicationAdapter extends RESTAdapter {
+export default class ApplicationAdapter extends RESTAdapter.extend(
+  AdapterBuildURLMixin
+) {
   // =attributes
 
   /**

addons/api/addon/mixins/adapter-build-url.js

@@ -0,0 +1,78 @@
+import Mixin from '@ember/object/mixin';
+import { get } from '@ember/object';
+
+/**
+ * Overrides URL-building methods in an adpater for greater flexibility.
+ * Specifically enhances calls to `urlPrefix` with `modelName`, `id`, and
+ * `snapshot`, which aren't normally passed.  And adds support for a
+ * `urlSuffix` method, the return value of which is appended to the end of
+ * a generated URL.
+ *
+ * While this mixin provides an enhanced API, it doesn't actually change the
+ * way URLs are generated by default.  Override methods in the adapter that
+ * uses this mixin to alter generated URLs.
+ */
+export default Mixin.create({
+
+  // =methods
+
+
+    /**
+     * This override behaves identically to the default method by default.
+     * It exists only to document the additional paramters to the method.
+     * @override
+     * @param {string} path
+     * @param {string} parentURL
+     * @param {string} modelName
+     * @param {string} id
+     * @param {object} snapshot
+     * @return {string} urlPrefix
+     */
+    urlPrefix(/* path, parentURL, modelName, id, snapshot */) {
+      // What's this super syntax?
+      // Ember mixins are still based on the older Ember Object, rather than
+      // native ES classes.  Thus we have to call super in this strange way.
+      // https://blog.emberjs.com/2019/01/26/emberjs-native-class-update-2019-edition.html
+      return this._super(...arguments);
+    },
+
+    /**
+     * Generates a string to be appended to a URL.  Empty string by default.
+     * @param {string} modelName
+     * @param {string} id
+     * @param {?object} snapshot
+     * @return {string}
+     */
+    urlSuffix(/* modelName, id, snapshot */) {
+      return '';
+    },
+
+  /**
+   * Overrides the default `_buildURL` with a nearly identical version.
+   * This method simply passes arguments into the `urlPrefix` method for
+   * convenience, where by default it receives no arguments.
+   *
+   * Adds a suffix, generated by the `urlSuffix` method, to the URL.
+   * @override
+   * @param {String} modelName
+   * @param {String} id
+   * @return {String} url
+   */
+  _buildURL(modelName, id, snapshot) {
+    let path;
+    let url = [];
+    const host = get(this, 'host');
+    const prefix = this.urlPrefix(null, null, modelName, id, snapshot);
+    const suffix = this.urlSuffix(modelName, id, snapshot);
+    if (modelName) {
+      path = this.pathForType(modelName);
+      if (path) url.push(path);
+    }
+    if (id) url.push(encodeURIComponent(id));
+    if (prefix) url.unshift(prefix);
+    url = url.join('/');
+    if (!host && url && url.charAt(0) !== '/') url = '/' + url;
+    return `${url}${suffix}`;
+  }
+
+});

addons/api/tests/unit/mixins/adapter-build-url-test.js

@@ -0,0 +1,55 @@
+import RESTAdapter from '@ember-data/adapter/rest';
+import AdapterBuildURLMixin from 'api/mixins/adapter-build-url';
+import { module, test } from 'qunit';
+import { setupTest } from 'ember-qunit';
+
+module('Unit | Mixin | build-url', function(hooks) {
+  setupTest(hooks);
+
+  test('it does not interfere with basic URLs', function (assert) {
+    assert.expect(1);
+    const Adapter = RESTAdapter.extend(AdapterBuildURLMixin);
+    this.owner.register('adapter:adapter', Adapter);
+    const adapter = this.owner.lookup('adapter:adapter');
+    const url = adapter._buildURL('model', 1);
+    assert.equal(url, '/models/1');
+  });
+
+  test('it does not interfere with namespaced URLs', function (assert) {
+    assert.expect(1);
+    const Adapter = RESTAdapter.extend(AdapterBuildURLMixin, {
+      namespace: 'api/v1'
+    });
+    this.owner.register('adapter:adapter', Adapter);
+    const adapter = this.owner.lookup('adapter:adapter');
+    const url = adapter._buildURL('model', 1);
+    assert.equal(url, '/api/v1/models/1');
+  });
+
+  test('it can prepend a prefix', function (assert) {
+    assert.expect(1);
+    const Adapter = RESTAdapter.extend(AdapterBuildURLMixin, {
+      urlPrefix() {
+        return '/foo/bars'
+      }
+    });
+    this.owner.register('adapter:adapter', Adapter);
+    const adapter = this.owner.lookup('adapter:adapter');
+    const url = adapter._buildURL('model', 1);
+    assert.equal(url, '/foo/bars/models/1');
+  });
+
+  test('it can append a suffix', function (assert) {
+    assert.expect(1);
+    const Adapter = RESTAdapter.extend(AdapterBuildURLMixin, {
+      urlSuffix() {
+        return ':method'
+      }
+    });
+    this.owner.register('adapter:adapter', Adapter);
+    const adapter = this.owner.lookup('adapter:adapter');
+    const url = adapter._buildURL('model', 1);
+    assert.equal(url, '/models/1:method');
+  });
+
+});