Gh-2972: Codecov can generate inconsistent coverage reports

.github/workflows/continuous-integration.yaml

@@ -89,7 +89,6 @@ jobs:
           - os: windows-latest
             modules:
               name: Rest
-
     env:
       MAVEN_OPTS: -Dmaven.wagon.http.retryHandler.count=3 -Dmaven.wagon.httpconnectionManager.ttlSeconds=25
     steps:
@@ -122,6 +121,29 @@ jobs:
         if: github.event_name == 'pull_request' && matrix.os == 'ubuntu-latest'
         run: mvn -B -ntp spotless:check -pl ${{matrix.modules.values}}
 
-      - name: Upload Coverage
+      - name: Add JaCoCo reports to artifact
+        uses: actions/upload-artifact@v3
         if: matrix.os == 'ubuntu-latest'
+        with:
+          name: combined-jacoco-coverage
+          path: "*/**/jacoco.xml"
+          retention-days: 5
+
+  upload-test-coverage:
+    name: Upload coverage to Codecov
+    runs-on: ubuntu-latest
+    needs:
+      - build-and-run-tests
+    steps:
+      - uses: actions/checkout@v3 # Codecov need to see the src code to pair with coverage
+
+      - name: Fetch JaCoCo reports artifact
+        uses: actions/download-artifact@v3
+        with:
+          name: combined-jacoco-coverage
+
+      - name: Upload to Codecov
         uses: codecov/codecov-action@v3
+        with:
+          name: gaffer-coverage
+          fail_ci_if_error: true # Ensures upload doesn't fail silently

example/pom.xml

@@ -1,5 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
 <!--
-  ~ Copyright 2016-2020 Crown Copyright
+  ~ Copyright 2016-2023 Crown Copyright
   ~
   ~ Licensed under the Apache License, Version 2.0 (the "License");
   ~ you may not use this file except in compliance with the License.
@@ -31,17 +32,4 @@
         <module>basic</module>
         <module>federated-demo</module>
     </modules>
-
-    <build>
-        <plugins>
-            <plugin>
-                <groupId>org.jacoco</groupId>
-                <artifactId>jacoco-maven-plugin</artifactId>
-                <version>${jacoco.plugin.version}</version>
-                <configuration>
-                    <skip>true</skip>
-                </configuration>
-            </plugin>
-        </plugins>
-    </build>
 </project>