From a13a04a7e9702e56f29dfba8926a30c925190f8a Mon Sep 17 00:00:00 2001
From: Demetrio Girardi <dgirardi@prebid.org>
Date: Tue, 11 Jan 2022 12:58:41 -0800
Subject: [PATCH] RTD module: allow submodules to setBidRequestData without
 `waitForIt` (#7862)

This change allows all RTD submodules at least one shot to see the `setBidRequestData` hook even if they are not flagged `waitForIt` (previously they would not be run at all in some cases).

Addresses https://github.com/prebid/Prebid.js/issues/7117
---
 modules/rtdModule/index.js                   | 15 +++---
 test/spec/modules/realTimeDataModule_spec.js | 53 +++++++++++++++++++-
 2 files changed, 57 insertions(+), 11 deletions(-)

diff --git a/modules/rtdModule/index.js b/modules/rtdModule/index.js
index 67326e7d887..6c88d66999a 100644
--- a/modules/rtdModule/index.js
+++ b/modules/rtdModule/index.js
@@ -291,18 +291,12 @@ export function setBidRequestsData(fn, reqBidsConfigObj) {
     return exitHook();
   }
 
-  if (shouldDelayAuction) {
-    waitTimeout = setTimeout(exitHook, _moduleConfig.auctionDelay);
-  }
+  waitTimeout = setTimeout(exitHook, shouldDelayAuction ? _moduleConfig.auctionDelay : 0);
 
   relevantSubModules.forEach(sm => {
     sm.getBidRequestData(reqBidsConfigObj, onGetBidRequestDataCallback.bind(sm), sm.config, _userConsent)
   });
 
-  if (!shouldDelayAuction) {
-    return exitHook();
-  }
-
   function onGetBidRequestDataCallback() {
     if (isDone) {
       return;
@@ -310,12 +304,15 @@ export function setBidRequestsData(fn, reqBidsConfigObj) {
     if (this.config && this.config.waitForIt) {
       callbacksExpected--;
     }
-    if (callbacksExpected <= 0) {
-      return exitHook();
+    if (callbacksExpected === 0) {
+      setTimeout(exitHook, 0);
     }
   }
 
   function exitHook() {
+    if (isDone) {
+      return;
+    }
     isDone = true;
     clearTimeout(waitTimeout);
     fn.call(this, reqBidsConfigObj);
diff --git a/test/spec/modules/realTimeDataModule_spec.js b/test/spec/modules/realTimeDataModule_spec.js
index 6538dec37c4..11639733661 100644
--- a/test/spec/modules/realTimeDataModule_spec.js
+++ b/test/spec/modules/realTimeDataModule_spec.js
@@ -141,7 +141,56 @@ describe('Real time module', function () {
       const adUnits = rtdModule.getAdUnitTargeting(auction);
       assert.deepEqual(expectedAdUnits, adUnits)
       done();
-    })
+    });
+
+    describe('setBidRequestData', () => {
+      let withWait, withoutWait;
+
+      function runSetBidRequestData() {
+        return new Promise((resolve) => {
+          rtdModule.setBidRequestsData(resolve, {bidRequest: {}});
+        });
+      }
+
+      beforeEach(() => {
+        withWait = {
+          submod: validSMWait,
+          cbTime: 0,
+          cbRan: false
+        };
+        withoutWait = {
+          submod: validSM,
+          cbTime: 0,
+          cbRan: false
+        };
+
+        [withWait, withoutWait].forEach((c) => {
+          c.submod.getBidRequestData = sinon.stub().callsFake((_, cb) => {
+            setTimeout(() => {
+              c.cbRan = true;
+              cb();
+            }, c.cbTime);
+          });
+        });
+      });
+
+      it('should allow non-priority submodules to run synchronously', () => {
+        withWait.cbTime = withoutWait.cbTime = 0;
+        return runSetBidRequestData().then(() => {
+          expect(withWait.cbRan).to.be.true;
+          expect(withoutWait.cbRan).to.be.true;
+        })
+      });
+
+      it('should not wait for non-priority submodules if priority ones complete first', () => {
+        withWait.cbTime = 10;
+        withoutWait.cbTime = 100;
+        return runSetBidRequestData().then(() => {
+          expect(withWait.cbRan).to.be.true;
+          expect(withoutWait.cbRan).to.be.false;
+        });
+      });
+    });
   });
 
   it('deep merge object', function () {
@@ -255,5 +304,5 @@ describe('Real time module', function () {
         expect(providers[1][hook].called).to.be.true;
       });
     });
-  })
+  });
 });