Add getShowSasCallbacks, getShowQrCodeCallbacks to VerifierBase (#3422)

* Add `getShowSasCallbacks`, `getShowQrCodeCallbacks` to VerifierBase

... to avoid some type-casting

* Integration test for QR code verification

Followup to #3436: another
integration test, this time using the QR code flow

* Rename method

... it turns out not to be used quite as I thought.

* tests for new methods

* Use Object.defineProperty, and restore afterwards

Apparently global.crypto exists in some environments

* apply ts-ignore

* More test coverage

* fix bad merge

Author: richvdh

spec/integ/crypto/verification.spec.ts

@@ -170,6 +170,7 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("verification (%s)", (backend: st
         // there should now be a verifier
         const verifier: VerificationBase = request.verifier!;
         expect(verifier).toBeDefined();
+        expect(verifier.getShowSasCallbacks()).toBeNull();
 
         // start off the verification process: alice will send an `accept`
         const verificationPromise = verifier.verify();
@@ -205,6 +206,10 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("verification (%s)", (backend: st
             verifier.once(VerifierEvent.ShowSas, resolve);
         });
 
+        // `getShowSasCallbacks` is an alternative way to get the callbacks
+        expect(verifier.getShowSasCallbacks()).toBe(showSas);
+        expect(verifier.getReciprocateQrCodeCallbacks()).toBeNull();
+
         // user confirms that the emoji match, and alice sends a 'mac'
         [requestBody] = await Promise.all([expectSendToDeviceMessage("m.key.verification.mac"), showSas.confirm()]);
         toDeviceMessage = requestBody.messages[TEST_USER_ID][TEST_DEVICE_ID];
@@ -320,13 +325,18 @@ describe.each(Object.entries(CRYPTO_BACKENDS))("verification (%s)", (backend: st
             // there should now be a verifier
             const verifier: VerificationBase = request.verifier!;
             expect(verifier).toBeDefined();
+            expect(verifier.getReciprocateQrCodeCallbacks()).toBeNull();
 
             // ... which we call .verify on, which emits a ShowReciprocateQr event
             const verificationPromise = verifier.verify();
             const reciprocateQRCodeCallbacks = await new Promise<ShowQrCodeCallbacks>((resolve) => {
                 verifier.once(VerifierEvent.ShowReciprocateQr, resolve);
             });
 
+            // getReciprocateQrCodeCallbacks() is an alternative way to get the callbacks
+            expect(verifier.getReciprocateQrCodeCallbacks()).toBe(reciprocateQRCodeCallbacks);
+            expect(verifier.getShowSasCallbacks()).toBeNull();
+
             // Alice confirms she is happy
             reciprocateQRCodeCallbacks.confirm();
 

src/crypto/verification/Base.ts

@@ -29,7 +29,12 @@ import { IVerificationChannel } from "./request/Channel";
 import { MatrixClient } from "../../client";
 import { VerificationRequest } from "./request/VerificationRequest";
 import { TypedEventEmitter } from "../../models/typed-event-emitter";
-import { VerifierEvent, VerifierEventHandlerMap } from "../../crypto-api/verification";
+import {
+    ShowQrCodeCallbacks,
+    ShowSasCallbacks,
+    VerifierEvent,
+    VerifierEventHandlerMap,
+} from "../../crypto-api/verification";
 
 const timeoutException = new Error("Verification timed out");
 
@@ -373,4 +378,24 @@ export class VerificationBase<
     public get events(): string[] | undefined {
         return undefined;
     }
+
+    /**
+     * Get the details for an SAS verification, if one is in progress
+     *
+     * Returns `null`, unless this verifier is for a SAS-based verification and we are waiting for the user to confirm
+     * the SAS matches.
+     */
+    public getShowSasCallbacks(): ShowSasCallbacks | null {
+        return null;
+    }
+
+    /**
+     * Get the details for reciprocating QR code verification, if one is in progress
+     *
+     * Returns `null`, unless this verifier is for reciprocating a QR-code-based verification (ie, the other user has
+     * already scanned our QR code), and we are waiting for the user to confirm.
+     */
+    public getReciprocateQrCodeCallbacks(): ShowQrCodeCallbacks | null {
+        return null;
+    }
 }

src/crypto/verification/QRCode.ts

@@ -119,6 +119,10 @@ export class ReciprocateQRCode extends Base {
             }
         });
     };
+
+    public getReciprocateQrCodeCallbacks(): ShowQrCodeCallbacks | null {
+        return this.reciprocateQREvent ?? null;
+    }
 }
 
 const CODE_VERSION = 0x02; // the version of binary QR codes we support

src/crypto/verification/SAS.ts

@@ -480,4 +480,8 @@ export class SAS extends Base {
             }
         });
     }
+
+    public getShowSasCallbacks(): ShowSasCallbacks | null {
+        return this.sasEvent ?? null;
+    }
 }