chore: split context.ts into files (#284)

src/pageSnapshot.ts

@@ -0,0 +1,101 @@
+/**
+ * Copyright (c) Microsoft Corporation.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import * as playwright from 'playwright';
+import yaml from 'yaml';
+
+type PageOrFrameLocator = playwright.Page | playwright.FrameLocator;
+
+export class PageSnapshot {
+  private _frameLocators: PageOrFrameLocator[] = [];
+  private _text!: string;
+
+  constructor() {
+  }
+
+  static async create(page: playwright.Page): Promise<PageSnapshot> {
+    const snapshot = new PageSnapshot();
+    await snapshot._build(page);
+    return snapshot;
+  }
+
+  text(): string {
+    return this._text;
+  }
+
+  private async _build(page: playwright.Page) {
+    const yamlDocument = await this._snapshotFrame(page);
+    this._text = [
+      `- Page Snapshot`,
+      '```yaml',
+      yamlDocument.toString({ indentSeq: false }).trim(),
+      '```',
+    ].join('\n');
+  }
+
+  private async _snapshotFrame(frame: playwright.Page | playwright.FrameLocator) {
+    const frameIndex = this._frameLocators.push(frame) - 1;
+    const snapshotString = await frame.locator('body').ariaSnapshot({ ref: true, emitGeneric: true });
+    const snapshot = yaml.parseDocument(snapshotString);
+
+    const visit = async (node: any): Promise<unknown> => {
+      if (yaml.isPair(node)) {
+        await Promise.all([
+          visit(node.key).then(k => node.key = k),
+          visit(node.value).then(v => node.value = v)
+        ]);
+      } else if (yaml.isSeq(node) || yaml.isMap(node)) {
+        node.items = await Promise.all(node.items.map(visit));
+      } else if (yaml.isScalar(node)) {
+        if (typeof node.value === 'string') {
+          const value = node.value;
+          if (frameIndex > 0)
+            node.value = value.replace('[ref=', `[ref=f${frameIndex}`);
+          if (value.startsWith('iframe ')) {
+            const ref = value.match(/\[ref=(.*)\]/)?.[1];
+            if (ref) {
+              try {
+                const childSnapshot = await this._snapshotFrame(frame.frameLocator(`aria-ref=${ref}`));
+                return snapshot.createPair(node.value, childSnapshot);
+              } catch (error) {
+                return snapshot.createPair(node.value, '<could not take iframe snapshot>');
+              }
+            }
+          }
+        }
+      }
+
+      return node;
+    };
+    await visit(snapshot.contents);
+    return snapshot;
+  }
+
+  refLocator(ref: string): playwright.Locator {
+    let frame = this._frameLocators[0];
+    const match = ref.match(/^f(\d+)(.*)/);
+    if (match) {
+      const frameIndex = parseInt(match[1], 10);
+      frame = this._frameLocators[frameIndex];
+      ref = match[2];
+    }
+
+    if (!frame)
+      throw new Error(`Frame does not exist. Provide ref from the most current snapshot.`);
+
+    return frame.locator(`aria-ref=${ref}`);
+  }
+}