Fix cucumber#1228: Added explicit checks for Null on JsonObject

This fix works around the limitation of minimal-json, that null as default is not handled (see ralfstx/minimal-json#103 (comment))

create-meta/java/src/main/java/io/cucumber/createmeta/CreateMeta.java

@@ -2,6 +2,7 @@
 
 import com.eclipsesource.json.Json;
 import com.eclipsesource.json.JsonObject;
+import com.eclipsesource.json.JsonValue;
 import io.cucumber.messages.Messages;
 import io.cucumber.messages.ProtocolVersion;
 
@@ -81,13 +82,13 @@ static Messages.Meta.CI detectCI(Map<String, String> env) {
     }
 
     private static Messages.Meta.CI createCi(String name, JsonObject ciSystem, Map<String, String> env) {
-        String url = evaluate(ciSystem.getString("url", null), env);
+        String url = evaluate(getString(ciSystem, "url"), env);
         if (url == null) return null;
         JsonObject git = ciSystem.get("git").asObject();
-        String remote = removeUserInfoFromUrl(evaluate(git.getString("remote", null), env));
-        String revision = evaluate(git.getString("revision", null), env);
-        String branch = evaluate(git.getString("branch", null), env);
-        String tag = evaluate(git.getString("tag", null), env);
+        String remote = removeUserInfoFromUrl(evaluate(getString(git, "remote"), env));
+        String revision = evaluate(getString(git, "revision"), env);
+        String branch = evaluate(getString(git, "branch"), env);
+        String tag = evaluate(getString(git, "tag"), env);
 
         Messages.Meta.CI.Builder ciBuilder = Messages.Meta.CI.newBuilder()
                 .setName(name)
@@ -144,4 +145,9 @@ private static String group1(String value, Pattern pattern) {
         }
         return matcher.find() ? matcher.group(1) : null;
     }
+
+    private static String getString(JsonObject json, String name) {
+        JsonValue val = json.get(name);
+        return val.isNull() ? null : val.asString();
+    }
 }

create-meta/java/src/test/java/io/cucumber/createmeta/CreateMetaTest.java

@@ -56,4 +56,21 @@ void it_detects_github_actions() {
                 meta.getCi());
     }
 
+    @Test
+    void can_handle_CIs_with_null_in_ciDict() {
+        // choose gocd as example, which has null everywhere except for url and revision
+        HashMap<String, String> env = new HashMap<String, String>() {{
+            put("GO_SERVER_URL", "https://<cihost>/buildurl");
+            put("GO_REVISION", "the-revision");
+        }};
+        Messages.Meta meta = CreateMeta.createMeta("cucumber-jvm", "3.2.1", env);
+        assertEquals(Messages.Meta.CI.newBuilder()
+                        .setName("GoCD")
+                        .setUrl("https://<cihost>/buildurl/???")
+                        .setGit(Messages.Meta.CI.Git.newBuilder()
+                                .setRevision("the-revision")
+                        )
+                        .build(),
+                meta.getCi());
+    }
 }

create-meta/testdata/GoCD.txt

@@ -0,0 +1,2 @@
+GO_SERVER_URL=https://cihost.com/path/to/the/build
+GO_REVISION=decafbad

create-meta/testdata/GoCD.txt.json

@@ -0,0 +1,7 @@
+{
+  "git": {
+    "revision": "decafbad"
+  },
+  "name": "GoCD",
+  "url": "https://cihost.com/path/to/the/build/???"
+}