Support build scan link for CircleCI

Detects running on CircleCI and configures the build scan with a link to the CI build job URL.

Author: shakuzen

src/main/java/io/spring/ge/conventions/gradle/BuildScanConventions.java

@@ -98,7 +98,7 @@ private void tagCiOrLocal(BuildScanExtension buildScan) {
 }
 
 private boolean isCi() {
-if (isBamboo() || isConcourse() || isJenkins()) {
+if (isBamboo() || isCircleCi() || isConcourse() || isJenkins()) {
 return true;
 }
 return false;
@@ -108,6 +108,10 @@ private boolean isBamboo() {
 return this.env.containsKey(BAMBOO_RESULTS_ENV_VAR);
 }
 
+private boolean isCircleCi() {
+return this.env.containsKey("CIRCLECI");
+}
+
 private boolean isConcourse() {
 return this.env.containsKey("CI");
 }
@@ -157,6 +161,9 @@ else if (isJenkins()) {
 buildScan.link("CI build", buildUrl);
 }
 }
+else if (isCircleCi()) {
+buildScan.link("CI build", this.env.get("CIRCLE_BUILD_URL"));
+}
 }
 
 private RunResult getBranch() {

src/test/java/io/spring/ge/conventions/gradle/BuildScanConventionsTests.java

@@ -81,6 +81,15 @@ void whenBambooResultEnvVarIsPresentThenBuildScanHasACiBuildLinkToIt() {
 assertThat(this.buildScan.links).containsEntry("CI build", "https://bamboo.example.com");
 }
 
+@Test
+void whenCircleCiAndCircleBuildUrlEnvVarsArePresentThenBuildScanHasACiBuildLinkToIt() {
+Map<String, String> env = new HashMap<>();
+env.put("CIRCLECI", "true");
+env.put("CIRCLE_BUILD_URL", "https://circleci.example.com/gh/org/project/123");
+new BuildScanConventions(this.processRunner, env).execute(this.buildScan);
+assertThat(this.buildScan.links).containsEntry("CI build", "https://circleci.example.com/gh/org/project/123");
+}
+
 @Test
 void whenJenkinsUrlAndBuildUrlEnvVarsArePresentThenBuildScanHasACiBuildLinkToBuildUrl() {
 Map<String, String> env = new HashMap<>();