add first parent option

Author: yanamura

action.yml

@@ -9,6 +9,10 @@ inputs:
     description: "to tag"
     required: false
     default: "latest"
+  first-parent:
+    description: "whether use --first-parent ro not"
+    required: false
+    default: true
 runs:
   using: "node12"
   main: "dist/index.js"

dist/index.js

@@ -1022,6 +1022,7 @@ function run() {
     return __awaiter(this, void 0, void 0, function* () {
         const from = core.getInput('from');
         const to = core.getInput('to');
+        const shouldUseFirstParent = core.getInput('first-parent');
         let output = '';
         const options = {
             listeners: {
@@ -1044,7 +1045,8 @@ function run() {
             core.setFailed('from or to is invalid');
             return;
         }
-        const command = `git log ${fromTag}..${toTag} --merges --reverse --pretty=format:"* %b"`;
+        const firstParentOption = shouldUseFirstParent ? '--first-parent' : '';
+        const command = `git log ${fromTag}..${toTag} --merges ${firstParentOption} --reverse --pretty=format:"* %b"`;
         core.info(command);
         yield exec.exec(command, [], options).catch(error => {
             core.setFailed(error.message);

src/main.ts

@@ -19,6 +19,7 @@ function getTag(tags: string[], name: string): string {
 async function run(): Promise<void> {
   const from = core.getInput('from')
   const to = core.getInput('to')
+  const shouldUseFirstParent = core.getInput('first-parent')
 
   let output = ''
   const options = {
@@ -48,7 +49,8 @@ async function run(): Promise<void> {
     return
   }
 
-  const command = `git log ${fromTag}..${toTag} --merges --reverse --pretty=format:"* %b"`
+  const firstParentOption = shouldUseFirstParent ? '--first-parent' : ''
+  const command = `git log ${fromTag}..${toTag} --merges ${firstParentOption} --reverse --pretty=format:"* %b"`
   core.info(command)
 
   await exec.exec(command, [], options).catch(error => {