Add profile to test against okhttp4 as well to verify backwards compatibility

Author: matthewelwell

.github/workflows/run-tests.yml

@@ -14,6 +14,12 @@ jobs:
       matrix:
         java: [ "11", "17", "21" ]
         distribution: [ "zulu", "adopt" ]
+        okhttp: [ "okhttp5", "okhttp4" ]
+        include:
+          - okhttp: "okhttp5"
+            maven_profiles: ""
+          - okhttp: "okhttp4"
+            maven_profiles: "-P test-okhttp4"
 
     steps:
       - name: Checkout repository
@@ -31,8 +37,8 @@ jobs:
         uses: actions/cache@v4
         with:
           path: ~/.m2
-          key: ${{ runner.os }}-m2-${{ hashFiles('**/pom.xml') }}
+          key: ${{ runner.os }}-m2-${{ matrix.okhttp }}-${{ hashFiles('**/pom.xml') }}
           restore-keys: ${{ runner.os }}-m2
 
-      - name: Build with Maven
-        run: mvn clean install
+      - name: Build with Maven (OkHttp ${{ matrix.okhttp }})
+        run: mvn clean install ${{ matrix.maven_profiles }}

pom.xml

@@ -48,13 +48,17 @@
     <slf4j.version>1.7.30</slf4j.version>
     <maven.checkstyle.version>3.4.0</maven.checkstyle.version>
     <junit.jupiter.version>5.14.0</junit.jupiter.version>
+    <!-- OkHttp dependency coordinates — overridden by the test-okhttp4 profile -->
+    <okhttp.artifactId>okhttp-jvm</okhttp.artifactId>
+    <okhttp.version>5.0.0</okhttp.version>
+    <okhttp.mockwebserver.version>5.0.0</okhttp.mockwebserver.version>
   </properties>
 
   <dependencies>
     <dependency>
       <groupId>com.squareup.okhttp3</groupId>
-      <artifactId>okhttp-jvm</artifactId>
-      <version>5.0.0</version>
+      <artifactId>${okhttp.artifactId}</artifactId>
+      <version>${okhttp.version}</version>
     </dependency>
     <dependency>
       <groupId>com.jayway.jsonpath</groupId>
@@ -157,7 +161,7 @@
     <dependency>
       <groupId>com.squareup.okhttp3</groupId>
       <artifactId>mockwebserver</artifactId>
-      <version>5.0.0</version>
+      <version>${okhttp.mockwebserver.version}</version>
       <scope>test</scope>
     </dependency>
     <dependency>
@@ -368,5 +372,17 @@
         </plugins>
       </build>
     </profile>
+    <profile>
+      <!--
+        Run the test suite against OkHttp 4.x to verify backward compatibility.
+        Activate with: mvn test -P test-okhttp4
+      -->
+      <id>test-okhttp4</id>
+      <properties>
+        <okhttp.artifactId>okhttp</okhttp.artifactId>
+        <okhttp.version>4.12.0</okhttp.version>
+        <okhttp.mockwebserver.version>4.12.0</okhttp.mockwebserver.version>
+      </properties>
+    </profile>
   </profiles>
 </project>