try fix base tree

src/create-or-update-branch.ts

@@ -142,6 +142,7 @@ interface CreateOrUpdateBranchResult {
   action: string
   base: string
   hasDiffWithBase: boolean
+  baseSha: string
   headSha: string
   branchCommits: Commit[]
 }
@@ -173,6 +174,7 @@ export async function createOrUpdateBranch(
     action: 'none',
     base: base,
     hasDiffWithBase: false,
+    baseSha: '',
     headSha: '',
     branchCommits: []
   }
@@ -322,8 +324,9 @@ export async function createOrUpdateBranch(
   // Build the branch commits
   result.branchCommits = await buildBranchCommits(git, base, branch)
 
-  // Get the pull request branch SHA
-  result.headSha = await git.revParse('HEAD')
+  // Get the base and head SHAs
+  result.baseSha = await git.revParse(base)
+  result.headSha = await git.revParse(branch)
 
   // Delete the temporary branch
   await git.exec(['branch', '--delete', '--force', tempBranch])

src/create-pull-request.ts

@@ -201,6 +201,7 @@ export async function createPullRequest(inputs: Inputs): Promise<void> {
         await git.checkout(inputs.branch)
         await githubHelper.pushSignedCommits(
           result.branchCommits,
+          result.baseSha,
           repoPath,
           branchRepository,
           inputs.branch

src/github-helper.ts

@@ -195,19 +195,35 @@ export class GitHubHelper {
 
   async pushSignedCommits(
     branchCommits: Commit[],
+    baseSha: string,
     repoPath: string,
     branchRepository: string,
     branch: string
   ): Promise<void> {
-    let headSha = ''
+    let headSha = baseSha
+
+    // testing
+    if (branchCommits.length > 0 && branchCommits[0].parents[0] !== baseSha) {
+      throw new Error(
+        `The base commit ${baseSha} does not match the first commit's parent ${branchCommits[0].parents[0]}`
+      )
+    }
+
     for (const commit of branchCommits) {
-      headSha = await this.createCommit(commit, repoPath, branchRepository)
+      // TODO: The headSha of the previous commit should be passed and used as the parent.
+      headSha = await this.createCommit(
+        commit,
+        [headSha],
+        repoPath,
+        branchRepository
+      )
     }
     await this.createOrUpdateRef(branchRepository, branch, headSha)
   }
 
   private async createCommit(
     commit: Commit,
+    parents: string[],
     repoPath: string,
     branchRepository: string
   ): Promise<string> {
@@ -238,7 +254,7 @@ export class GitHubHelper {
       core.info(`Creating tree for local commit ${commit.sha}`)
       const {data: tree} = await this.octokit.rest.git.createTree({
         ...repository,
-        base_tree: commit.parents[0],
+        base_tree: parents[0],
         tree: treeObjects
       })
       treeSha = tree.sha
@@ -247,7 +263,7 @@ export class GitHubHelper {
 
     const {data: remoteCommit} = await this.octokit.rest.git.createCommit({
       ...repository,
-      parents: commit.parents,
+      parents: parents,
       tree: treeSha,
       message: `${commit.subject}\n\n${commit.body}`
     })