[Unified recorder] String sanitizer support + sanitizer refactor (Azure#19954)

- Fixes Azure#19809
- Part of work towards Azure#18223

The main motivation of this PR was to add support for the new string sanitizers introduced in Azure/azure-sdk-tools#2530. As part of this, I've also tackled some refactoring that will be required for session-level sanitizer support (Azure#18223) where we will be wanting to enable adding sanitizers without access to an instance of the `Recorder` class. While implementing the new sanitizer logic, I refactored the `addSanitizers` method into smaller chunks to make adding additional sanitizers easier. To summarize the changes:

* Removed the `Sanitizer` class, instead making the `addSanitizers` function in `sanitizer.ts` take in a `HttpClient` and recording ID as parameter.
* Refactored the `addSanitizers` function to call smaller functions for each sanitizer (some of which are a bit FP-style) instead of using if statements + special cases. Hopefully this will make things a bit easier to maintain.
* Some other minor refactors (e.g. extracting duplicated `createRecordingRequest` function into a utility).
* Add support for the string sanitizers in what I think is the most logical way, but there is a **breaking change**:
  * When calling `addSanitizers`, instead of specifying `generalRegexSanitizers: [...]` etc., you now specify `generalSanitizers: [...]`. Both regex sanitizers and string sanitizers can be used in this way, for example:
 ```ts
recorder.addSanitizers({
  generalSanitizers: [
    {
      regex: true, // Regex matching is enabled by setting the 'regex' option to true.
      target: ".*regex",
      value: "sanitized",
    },
    {
      // Note that `regex` defaults to false and doesn't need to be specified when working with bare strings.
      // In my experience, this is the most common scenario anyway.
      target: "Not a regex",
      value: "sanitized",
    }
  ],
});
```

Author: timovv

sdk/test-utils/recorder/CHANGELOG.md

@@ -2,6 +2,36 @@
 
 ## 2.0.0 (Unreleased)
 
+## 2022-01-27
+
+Add support for the new string sanitizers, including **breaking changes**:
+
+- Removed the `Sanitizer` class, instead making the `addSanitizers` function in `sanitizer.ts` take in a `HttpClient` and recording ID as parameter.
+- Refactored the `addSanitizers` function to call smaller functions for each sanitizer (some of which are a bit FP-style) instead of using if statements + special cases. Hopefully this will make things a bit easier to maintain.
+- Some other minor refactors (e.g. extracting duplicated `createRecordingRequest` function into a utility).
+- Add support for the string sanitizers in what I think is the most logical way, but there is a **breaking change**:
+  - When calling `addSanitizers`, instead of specifying `generalRegexSanitizers: [...]` etc., you now specify `generalSanitizers: [...]`. Both regex sanitizers and string sanitizers can be used in this way, for example:
+
+```ts
+recorder.addSanitizers({
+  generalSanitizers: [
+    {
+      regex: true, // Regex matching is enabled by setting the 'regex' option to true.
+      target: ".*regex",
+      value: "sanitized",
+    },
+    {
+      // Note that `regex` defaults to false and doesn't need to be specified when working with bare strings.
+      // In my experience, this is the most common scenario anyway.
+      target: "Not a regex",
+      value: "sanitized",
+    },
+  ],
+});
+```
+
+[#19954](https://github.com/Azure/azure-sdk-for-js/pull/19954)
+
 ## 2022-01-06
 
 - Renaming the package `@azure-tools/[email protected]` as `@azure-tools/[email protected]`.

sdk/test-utils/recorder/MIGRATION.md

@@ -15,7 +15,7 @@ The new recorder is version 2.0.0 of the `@azure-tools/test-recorder` package. U
   // ...
   "devDependencies": {
     // ...
-    "@azure-tools/test-recorder": "^2.0.0",
+    "@azure-tools/test-recorder": "^2.0.0"
   }
 }
 ```
@@ -152,23 +152,30 @@ In this example, the name of the queue used in the recording is randomized. Howe
 
 A powerful feature of the legacy recorder was its `customizationsOnRecordings` option, which allowed for arbitrary replacements to be made to recordings. The new recorder's analog to this is the sanitizer functionality.
 
-### GeneralRegexSanitizer
+### General sanitizers
 
-For a simple find/replace, a `GeneralRegexSanitizer` can be used. For example:
+For a simple find/replace, `generalSanitizers` can be used. For example:
 
 ```ts
 await recorder.addSanitizers({
-  generalRegexSanitizers: [
+  generalSanitizers: [
     {
-      regex: "find", // This should be a .NET regular expression as it is passed to the .NET proxy tool
+      target: "find", // With `regex` unspecified, this matches a plaintext string
+      value: "replace",
+    },
+    {
+      regex: true, // Enable regex matching
+      target: "[Rr]egex", // This is a .NET regular expression that will be compiled by the proxy tool.
       value: "replace",
     },
     // add additional sanitizers here as required
   ],
 });
 ```
 
-This example would replace all instances of `find` in the recording with `replace`.
+This example has two sanitizers: 
+- The first sanitizer replaces all instances of "find" in the recording with "replace". 
+- The second example demonstrates the use of a regular expression for replacement, where anything matching the .NET regular expression `[Rr]egex` (i.e. "Regex" and "regex") would be replaced with "replace".
 
 ### ConnectionStringSanitizer
 

sdk/test-utils/recorder/src/recorder.ts

@@ -3,9 +3,7 @@
 
 import {
   createDefaultHttpClient,
-  createPipelineRequest,
   HttpClient,
-  HttpMethods,
   Pipeline,
   PipelinePolicy,
   PipelineRequest,
@@ -27,7 +25,7 @@ import { Test } from "mocha";
 import { sessionFilePath } from "./utils/sessionFilePath";
 import { SanitizerOptions } from "./utils/utils";
 import { paths } from "./utils/paths";
-import { Sanitizer } from "./sanitizer";
+import { addSanitizers, transformsInfo } from "./sanitizer";
 import { handleEnvSetup } from "./utils/envSetupForPlayback";
 import { Matcher, setMatcher } from "./matcher";
 import {
@@ -37,6 +35,7 @@ import {
   WebResource,
   WebResourceLike,
 } from "@azure/core-http";
+import { createRecordingRequest } from "./utils/createRecordingRequest";
 
 /**
  * This client manages the recorder life cycle and interacts with the proxy-tool to do the recording,
@@ -55,7 +54,6 @@ export class Recorder {
   private stateManager = new RecordingStateManager();
   private httpClient?: HttpClient;
   private sessionFile?: string;
-  private sanitizer?: Sanitizer;
   private variables: Record<string, string>;
 
   constructor(private testContext?: Test | undefined) {
@@ -68,7 +66,6 @@ export class Recorder {
           "Unable to determine the recording file path, testContext provided is not defined."
         );
       }
-      this.sanitizer = new Sanitizer(this.url, this.httpClient);
     }
     this.variables = {};
   }
@@ -113,8 +110,12 @@ export class Recorder {
    */
   async addSanitizers(options: SanitizerOptions): Promise<void> {
     // If check needed because we only sanitize when the recording is being generated, and we need a recording to apply the sanitizers on.
-    if (isRecordMode() && ensureExistence(this.sanitizer, "this.sanitizer")) {
-      return this.sanitizer.addSanitizers(options);
+    if (
+      isRecordMode() &&
+      ensureExistence(this.httpClient, "this.httpClient") &&
+      ensureExistence(this.recordingId, "this.recordingId")
+    ) {
+      return addSanitizers(this.httpClient, this.url, this.recordingId, options);
     }
   }
 
@@ -135,7 +136,7 @@ export class Recorder {
       const startUri = `${this.url}${isPlaybackMode() ? paths.playback : paths.record}${
         paths.start
       }`;
-      const req = this._createRecordingRequest(startUri);
+      const req = createRecordingRequest(startUri, this.sessionFile, this.recordingId);
 
       if (ensureExistence(this.httpClient, "TestProxyHttpClient.httpClient")) {
         const rsp = await this.httpClient.sendRequest({
@@ -153,12 +154,14 @@ export class Recorder {
         if (isPlaybackMode()) {
           this.variables = rsp.bodyAsText ? JSON.parse(rsp.bodyAsText) : {};
         }
-        if (ensureExistence(this.sanitizer, "TestProxyHttpClient.sanitizer")) {
-          // Setting the recordingId in the sanitizer,
-          // the sanitizers added will take the recording id and only be part of the current test
-          this.sanitizer.setRecordingId(this.recordingId);
-          await handleEnvSetup(options.envSetupForPlayback, this.sanitizer);
-        }
+
+        await handleEnvSetup(
+          this.httpClient,
+          this.url,
+          this.recordingId,
+          options.envSetupForPlayback
+        );
+
         // Sanitizers to be added only in record mode
         if (isRecordMode() && options.sanitizerOptions) {
           // Makes a call to the proxy-tool to add the sanitizers for the current recording id
@@ -177,7 +180,7 @@ export class Recorder {
     this.stateManager.state = "stopped";
     if (this.recordingId !== undefined) {
       const stopUri = `${this.url}${isPlaybackMode() ? paths.playback : paths.record}${paths.stop}`;
-      const req = this._createRecordingRequest(stopUri);
+      const req = createRecordingRequest(stopUri, undefined, this.recordingId);
       req.headers.set("x-recording-save", "true");
 
       if (isRecordMode()) {
@@ -211,19 +214,16 @@ export class Recorder {
     }
   }
 
-  /**
-   * Adds the recording file and the recording id headers to the requests that are sent to the proxy tool.
-   * These are required to appropriately save the recordings in the record mode and picking them up in playback.
-   */
-  private _createRecordingRequest(url: string, method: HttpMethods = "POST") {
-    const req = createPipelineRequest({ url, method });
-    if (ensureExistence(this.sessionFile, "sessionFile")) {
-      req.body = JSON.stringify({ "x-recording-file": this.sessionFile });
+  async transformsInfo(): Promise<string | null | undefined> {
+    if (isLiveMode()) {
+      throw new RecorderError("Cannot call transformsInfo in live mode");
     }
-    if (this.recordingId !== undefined) {
-      req.headers.set("x-recording-id", this.recordingId);
+
+    if (ensureExistence(this.httpClient, "this.httpClient")) {
+      return await transformsInfo(this.httpClient, this.url, this.recordingId!);
     }
-    return req;
+
+    throw new RecorderError("Expected httpClient to be defined");
   }
 
   /**