Feature/5114 add parallel commit config

cypress/integration/rendering/gitGraph.spec.js

@@ -826,4 +826,121 @@ gitGraph TB:
       cherry-pick id: "M" parent:"B"`
     );
   });
+  it('41: should render default GitGraph with parallelCommits set to false', () => {
+    imgSnapshotTest(
+      `gitGraph
+      commit id:"1-abcdefg"
+      commit id:"2-abcdefg"
+      branch develop
+      commit id:"3-abcdefg"
+      commit id:"4-abcdefg"
+      checkout main
+      branch feature
+      commit id:"5-abcdefg"
+      commit id:"6-abcdefg"
+      checkout main
+      commit id:"7-abcdefg"
+      commit id:"8-abcdefg"
+      `,
+      { gitGraph: { parallelCommits: false } }
+    );
+  });
+  it('42: should render GitGraph with parallel commits', () => {
+    imgSnapshotTest(
+      `gitGraph
+      commit id:"1-abcdefg"
+      commit id:"2-abcdefg"
+      branch develop
+      commit id:"3-abcdefg"
+      commit id:"4-abcdefg"
+      checkout main
+      branch feature
+      commit id:"5-abcdefg"
+      commit id:"6-abcdefg"
+      checkout main
+      commit id:"7-abcdefg"
+      commit id:"8-abcdefg"
+      `,
+      { gitGraph: { parallelCommits: true } }
+    );
+  });
+  it('43: should render GitGraph with parallel commits | Vertical Branch', () => {
+    imgSnapshotTest(
+      `gitGraph TB:
+      commit id:"1-abcdefg"
+      commit id:"2-abcdefg"
+      branch develop
+      commit id:"3-abcdefg"
+      commit id:"4-abcdefg"
+      checkout main
+      branch feature
+      commit id:"5-abcdefg"
+      commit id:"6-abcdefg"
+      checkout main
+      commit id:"7-abcdefg"
+      commit id:"8-abcdefg"
+      `,
+      { gitGraph: { parallelCommits: true } }
+    );
+  });
+  it('44: should render GitGraph with unconnected branches and no parallel commits', () => {
+    imgSnapshotTest(
+      `gitGraph
+      branch dev
+      branch v2
+      branch feat
+      commit id:"1-abcdefg"
+      commit id:"2-abcdefg"
+      checkout main
+      commit id:"3-abcdefg"
+      checkout dev
+      commit id:"4-abcdefg"
+      checkout v2
+      commit id:"5-abcdefg"
+      checkout main
+      commit id:"6-abcdefg"
+      `,
+      { gitGraph: { parallelCommits: false } }
+    );
+  });
+  it('45: should render GitGraph with unconnected branches and parallel commits', () => {
+    imgSnapshotTest(
+      `gitGraph
+      branch dev
+      branch v2
+      branch feat
+      commit id:"1-abcdefg"
+      commit id:"2-abcdefg"
+      checkout main
+      commit id:"3-abcdefg"
+      checkout dev
+      commit id:"4-abcdefg"
+      checkout v2
+      commit id:"5-abcdefg"
+      checkout main
+      commit id:"6-abcdefg"
+      `,
+      { gitGraph: { parallelCommits: true } }
+    );
+  });
+  it('46: should render GitGraph with unconnected branches and parallel commits | Vertical Branch', () => {
+    imgSnapshotTest(
+      `gitGraph TB:
+      branch dev
+      branch v2
+      branch feat
+      commit id:"1-abcdefg"
+      commit id:"2-abcdefg"
+      checkout main
+      commit id:"3-abcdefg"
+      checkout dev
+      commit id:"4-abcdefg"
+      checkout v2
+      commit id:"5-abcdefg"
+      checkout main
+      commit id:"6-abcdefg"
+      `,
+      { gitGraph: { parallelCommits: true } }
+    );
+  });
 });

packages/mermaid/src/config.type.ts

@@ -576,6 +576,7 @@ export interface GitGraphDiagramConfig extends BaseDiagramConfig {
   showCommitLabel?: boolean;
   showBranches?: boolean;
   rotateCommitLabel?: boolean;
+  parallelCommits?: boolean;
   /**
    * Controls whether or arrow markers in html code are absolute paths or anchors.
    * This matters if you are using base tag settings.

packages/mermaid/src/diagrams/git/gitGraphRenderer.js

@@ -64,6 +64,29 @@ const drawText = (txt) => {
   return svgLabel;
 };
 
+/**
+ * Searches for the closest parent from the parents list passed as argument.
+ * The parents list comes from an individual commit. The closest parent is actually
+ * the one farther down the graph, since that means it is closer to its child.
+ *
+ * @param {string[]} parents
+ * @returns {string | undefined}
+ */
+const findClosestParent = (parents) => {
+  let closestParent = '';
+  let maxPosition = 0;
+
+  parents.forEach((parent) => {
+    const parentPosition = dir === 'TB' ? commitPos[parent].y : commitPos[parent].x;
+    if (parentPosition >= maxPosition) {
+      closestParent = parent;
+      maxPosition = parentPosition;
+    }
+  });
+
+  return closestParent || undefined;
+};
+
 /**
  * Draws the commits with its symbol and labels. The function has two modes, one which only
  * calculates the positions and one that does the actual drawing. This for a simple way getting the
@@ -87,9 +110,23 @@ const drawCommits = (svg, commits, modifyGraph) => {
   const sortedKeys = keys.sort((a, b) => {
     return commits[a].seq - commits[b].seq;
   });
+
+  const isParallelCommits = gitGraphConfig.parallelCommits;
   sortedKeys.forEach((key) => {
     const commit = commits[key];
 
+    if (isParallelCommits) {
+      if (!commit.parents.length) {
+        pos = 0;
+        if (dir === 'TB') {
+          pos = 30;
+        }
+      } else {
+        const closestParent = findClosestParent(commit.parents);
+        pos = dir === 'TB' ? commitPos[closestParent].y + 40 : commitPos[closestParent].x + 40;
+      }
+    }
+
     const y = dir === 'TB' ? pos + 10 : branchPos[commit.branch].pos;
     const x = dir === 'TB' ? branchPos[commit.branch].pos : pos + 10;
 

packages/mermaid/src/schemas/config.schema.yaml

@@ -786,6 +786,9 @@ $defs: # JSON Schema definition (maybe we should move these to a separate file)
       rotateCommitLabel:
         type: boolean
         default: true
+      parallelCommits:
+        type: boolean
+        default: false
       # YAML anchor reference, don't use $ref since ajv doesn't load defaults
       arrowMarkerAbsolute: *arrowMarkerAbsolute