#1145: persist commit fields in MkCommits.create

MkCommits.create(JsonObject) used to delegate straight to get(sha) without
applying any Directives, so the commit node was never inserted into the
mock storage XML. Any subsequent call to MkCommit.json() (or any other
method that reads from the storage) raised NodeNotFoundException because
the XPath /github/repos/repo/git/commits/commit[sha=...] selected nothing.

The fix walks the input JsonObject and writes every key as an element
under the new <commit> node, mirroring how MkBranches.create and
MkReferences.create persist their inputs. Arrays are stored with the
@array attribute that JsonNode already understands, so MkCommit.json()
round-trips them as JsonArray. Nested objects (e.g. author) are stored
as nested elements.

Author: bibonix

src/main/java/com/jcabi/github/mock/MkCommits.java

@@ -12,7 +12,10 @@
 import com.jcabi.github.Repo;
 import com.jcabi.github.Statuses;
 import jakarta.json.JsonObject;
+import jakarta.json.JsonString;
+import jakarta.json.JsonValue;
 import java.io.IOException;
+import java.util.Map;
 import lombok.EqualsAndHashCode;
 import org.xembly.Directives;
 
@@ -74,7 +77,28 @@ public Repo repo() {
     @Override
     public Commit create(
         final JsonObject params
-    ) {
+    ) throws IOException {
+        final Directives dirs = new Directives().xpath(this.xpath()).add("commit");
+        for (final Map.Entry<String, JsonValue> entry : params.entrySet()) {
+            final JsonValue value = entry.getValue();
+            if (value.getValueType() == JsonValue.ValueType.ARRAY) {
+                dirs.add(entry.getKey()).attr("array", "true");
+                for (final JsonValue item : value.asJsonArray()) {
+                    dirs.add("item").set(MkCommits.asText(item)).up();
+                }
+                dirs.up();
+            } else if (value.getValueType() == JsonValue.ValueType.OBJECT) {
+                dirs.add(entry.getKey());
+                for (final Map.Entry<String, JsonValue> sub
+                    : value.asJsonObject().entrySet()) {
+                    dirs.add(sub.getKey()).set(MkCommits.asText(sub.getValue())).up();
+                }
+                dirs.up();
+            } else {
+                dirs.add(entry.getKey()).set(MkCommits.asText(value)).up();
+            }
+        }
+        this.storage.apply(dirs);
         return this.get(params.getString("sha"));
     }
 
@@ -91,4 +115,30 @@ public Statuses statuses(
     ) {
         return new MkStatuses(this.get(sha));
     }
+
+    /**
+     * XPath of the commits element in the storage XML.
+     * @return XPath
+     */
+    private String xpath() {
+        return String.format(
+            "/github/repos/repo[@coords='%s']/git/commits",
+            this.coords
+        );
+    }
+
+    /**
+     * Render JSON value as plain text suitable for XML storage.
+     * @param value JSON value
+     * @return Plain string
+     */
+    private static String asText(final JsonValue value) {
+        final String result;
+        if (value.getValueType() == JsonValue.ValueType.STRING) {
+            result = ((JsonString) value).getString();
+        } else {
+            result = value.toString();
+        }
+        return result;
+    }
 }