From 54195fdf14d0ec2b63e56f2d396927f6d402a853 Mon Sep 17 00:00:00 2001
From: Michael Peters <michael@styx>
Date: Thu, 6 Oct 2022 21:23:58 -0700
Subject: [PATCH] multi-request dedups with value

---
 src/client/tests/webapp/auto-verifier.test.ts | 101 +++++++++++++++++-
 src/client/webapp/auto-verifier.ts            |   2 +
 2 files changed, 101 insertions(+), 2 deletions(-)

diff --git a/src/client/tests/webapp/auto-verifier.test.ts b/src/client/tests/webapp/auto-verifier.test.ts
index 83ef042..b0d77b9 100644
--- a/src/client/tests/webapp/auto-verifier.test.ts
+++ b/src/client/tests/webapp/auto-verifier.test.ts
@@ -194,6 +194,37 @@ describe('fetchAndVerifyIfNeeded tests', () => {
 		}
 	}
 
+    function fetchAndVerifyIfNeededManually<T>(
+        av: AutoVerifier<T>,
+        nextPrimary: () => ManualPromise<T | null>,
+        nextTrusted: () => ManualPromise<T | null>,
+        nextEnsureTrustedFuncReady: () => ManualPromise<void>,
+        nextVerify: () => ManualPromise<boolean>,
+        lazyVerify: boolean = false,
+    ) {
+        const state: {
+            primary: ManualPromise<T | null>,
+            trusted: ManualPromise<T | null>,
+            ensureTrustedFuncReady: ManualPromise<void>,
+            verify: ManualPromise<boolean>,
+            result: T | null | undefined,
+            rejection: Error | undefined,
+        } = {
+            primary: nextPrimary(),
+            trusted: nextTrusted(),
+            ensureTrustedFuncReady: nextEnsureTrustedFuncReady(),
+            verify: nextVerify(),
+            result: undefined,
+            rejection: undefined,
+        }
+
+        const resultPromise = av.fetchAndVerifyIfNeeded(lazyVerify);
+        resultPromise.then((value) => { state.result = value; });
+        resultPromise.catch((value) => { state.rejection = value; });
+
+        return state;
+    }
+
 	async function disjoint() {
 		await Util.sleep(0);
 	}
@@ -709,7 +740,73 @@ describe('fetchAndVerifyIfNeeded tests', () => {
 		expect(verifyFunc).toHaveBeenCalledTimes(0);
 	});
 
+    test('ab, a: primary with value, b: primary dedup, ab: trusted dedup with value', async () => {
+		const {
+			nextPrimary, nextTrusted, nextEnsureTrustedFuncReady, nextVerify,
+			primaryFunc, trustedFunc, ensureTrustedFuncReadyFunc, verifyFunc
+		} = getManualsAndMocks();
+		
+        const av = new AutoVerifier(primaryFunc, trustedFunc, ensureTrustedFuncReadyFunc, verifyFunc);
+
+        const a = fetchAndVerifyIfNeededManually(av, nextPrimary, nextTrusted, nextEnsureTrustedFuncReady, nextVerify);
+
+        expect(av.primaryPromise).toBe(a.primary.promise);
+        expect(av.trustedPromise).toBe(a.trusted.promise);
+        expect(av.trustedStatus).toBe('fetching');
+		expect(primaryFunc).toHaveBeenCalled();
+		expect(trustedFunc).toHaveBeenCalled();
+
+        const b = fetchAndVerifyIfNeededManually(av, nextPrimary, nextTrusted, nextEnsureTrustedFuncReady, nextVerify);
+        
+        expect(av.primaryPromise).toBe(a.primary.promise); // doesn't change from a
+        expect(av.trustedPromise).toBe(a.trusted.promise); // doesn't change from a
+        expect(av.trustedStatus).toBe('fetching');
+        
+        expect(a.result).toBeUndefined();
+        expect(b.result).toBeUndefined();
+        a.primary.resolve(new BasicWE(2));
+        await disjoint();
+
+        expect(a.result).toEqual(new BasicWE(2));
+        expect(b.result).toEqual(new BasicWE(2));
+		expect(av.primaryPromise).toBe(null);
+		expect(av.trustedPromise).toBe(a.trusted.promise);
+		expect(av.trustedStatus).toBe('verifying');
+
+        a.ensureTrustedFuncReady.resolve();
+        await disjoint();
+
+		expect(av.primaryPromise).toBe(null);
+		expect(av.trustedPromise).toBe(a.trusted.promise);
+		expect(av.trustedStatus).toBe('verifying');
+
+        expect(verifyFunc).toHaveBeenCalledTimes(0);
+        a.trusted.resolve(new BasicWE(2));
+        await disjoint();
+
+        expect(verifyFunc).toHaveBeenCalledWith(new BasicWE(2), new BasicWE(2));
+		expect(av.primaryPromise).toBe(null);
+		expect(av.trustedPromise).toBe(a.trusted.promise);
+		expect(av.trustedStatus).toBe('verifying');
+
+        a.verify.resolve(true);
+        await disjoint();
+		
+        expect(av.primaryPromise).toBe(null);
+		expect(av.trustedPromise).toBe(a.trusted.promise);
+		expect(av.trustedStatus).toBe('verified');
+
+        await disjoint(); // sanity check
+
+        // Even though there were two fetchAnd... calls, they were deduped such that each func was only called once
+		expect(primaryFunc).toHaveBeenCalledTimes(1);
+		expect(trustedFunc).toHaveBeenCalledTimes(1);
+		expect(ensureTrustedFuncReadyFunc).toHaveBeenCalledTimes(1);
+		expect(verifyFunc).toHaveBeenCalledTimes(1);
+    });
+
 	// Make sure to do try/catch errors/rejections, verification failures, unverifies in the middle
-	// Multiple tryResolveTrustedPromises
-	// Multiple fetchAndVerifyIfNeeded at the same time
+	// Multiple tryResolveTrustedPromises - multiple fetchAndVerifyIfNeeded at the same time
+    // Trusted resolves *BEFORE* ensureTrustedFuncReady
+    // Fetching after verified doesn't re-fetch trusted
 });
diff --git a/src/client/webapp/auto-verifier.ts b/src/client/webapp/auto-verifier.ts
index 07e2062..f58973e 100644
--- a/src/client/webapp/auto-verifier.ts
+++ b/src/client/webapp/auto-verifier.ts
@@ -249,6 +249,8 @@ export class AutoVerifier<T> {
 								// no one has started verifying the trusted yet
 
 								this.trustedStatus = 'verifying';
+                                // TODO: I want to remove the ensureTrustedFuncReady func in favor
+                                // of just including it yourself in the trustedFunc
 								/* istanbul ignore next */
 								if (debug) LOG.debug(fetchId + ': verifying... (awaiting trustedPromise)');
 								await this.ensureTrustedFuncReady();