(WIP) some work

app/src/lib/git/rebase.ts

@@ -37,6 +37,11 @@ export enum RebaseResult {
    * signal success to the user.
    */
   CompletedWithoutError = 'CompletedWithoutError',
+  /**
+   * Git completed the rebase without reporting any errors, but the branch was
+   * already up to date and there was nothing to do.
+   */
+  BranchAlreadyUpToDate = 'BranchAlreadyUpToDate',
   /**
    * The rebase encountered conflicts while attempting to rebase, and these
    * need to be resolved by the user before the rebase can continue.
@@ -61,6 +66,17 @@ export enum RebaseResult {
   Error = 'Error',
 }
 
+export function isSuccessfulRebaseResult(
+  result: RebaseResult
+): result is
+  | RebaseResult.CompletedWithoutError
+  | RebaseResult.BranchAlreadyUpToDate {
+  return [
+    RebaseResult.CompletedWithoutError,
+    RebaseResult.BranchAlreadyUpToDate,
+  ].includes(result)
+}
+
 /**
  * Check the `.git/REBASE_HEAD` file exists in a repository to confirm
  * a rebase operation is underway.
@@ -402,6 +418,10 @@ export async function abortRebase(repository: Repository) {
 
 function parseRebaseResult(result: IGitResult): RebaseResult {
   if (result.exitCode === 0) {
+    if (result.stdout.trim().match(/^Current branch [^ ]+ is up to date.$/i)) {
+      return RebaseResult.BranchAlreadyUpToDate
+    }
+
     return RebaseResult.CompletedWithoutError
   }
 

app/src/ui/dispatcher/dispatcher.ts

@@ -33,6 +33,7 @@ import {
   getBranches,
   getRebaseSnapshot,
   getRepositoryType,
+  isSuccessfulRebaseResult,
 } from '../../lib/git'
 import { isGitOnPath } from '../../lib/is-git-on-path'
 import {
@@ -1211,7 +1212,7 @@ export class Dispatcher {
         baseBranch.name,
         targetBranch.name
       )
-    } else if (result === RebaseResult.CompletedWithoutError) {
+    } else if (isSuccessfulRebaseResult(result)) {
       if (tip.kind !== TipState.Valid) {
         log.warn(
           `[rebase] tip after completing rebase is ${tip.kind} but this should be a valid tip if the rebase completed without error`
@@ -1259,7 +1260,7 @@ export class Dispatcher {
       manualResolutions
     )
 
-    if (result === RebaseResult.CompletedWithoutError) {
+    if (result === RebaseResult.ConflictsEncountered) {
       this.statsStore.recordOperationSuccessfulWithConflicts(kind)
     }
 
@@ -3627,7 +3628,8 @@ export class Dispatcher {
     // conflict flow if squash results in conflict.
     const status = await this.appStore._loadStatus(repository)
     switch (result) {
-      case RebaseResult.CompletedWithoutError:
+      case (RebaseResult.CompletedWithoutError,
+      RebaseResult.BranchAlreadyUpToDate):
         if (status !== null && status.currentTip !== undefined) {
           // This sets the history to the current tip
           // TODO: Look at history back to last retained commit and search for
@@ -3642,7 +3644,9 @@ export class Dispatcher {
 
         await this.completeMultiCommitOperation(
           repository,
-          totalNumberOfCommits
+          result === RebaseResult.BranchAlreadyUpToDate
+            ? 0
+            : totalNumberOfCommits
         )
         break
       case RebaseResult.ConflictsEncountered:

app/src/ui/lib/update-branch.ts

@@ -1,4 +1,4 @@
-import { getCommitsBetweenCommits, getMergeBase } from '../../lib/git'
+import { getCommitsBetweenCommits } from '../../lib/git'
 import { promiseWithMinimumTimeout } from '../../lib/promise'
 import { Branch } from '../../models/branch'
 import { ComputedAction } from '../../models/computed-action'
@@ -42,21 +42,15 @@ export async function updateRebasePreview(
     kind: ComputedAction.Loading,
   })
 
-  const { commits, base } = await promiseWithMinimumTimeout(async () => {
+  const commits = await promiseWithMinimumTimeout(
-    const commits = await getCommitsBetweenCommits(
+    () =>
-      repository,
+      getCommitsBetweenCommits(
-      baseBranch.tip.sha,
+        repository,
-      targetBranch.tip.sha
+        baseBranch.tip.sha,
-    )
+        targetBranch.tip.sha
-
+      ),
-    const base = await getMergeBase(
+    500
-      repository,
+  )
-      baseBranch.tip.sha,
-      targetBranch.tip.sha
-    )
-
-    return { commits, base }
-  }, 500)
 
   // if the branch being track has changed since we started this work, abandon
   // any further state updates (this function is re-entrant if the user is
@@ -75,14 +69,8 @@ export async function updateRebasePreview(
     return
   }
 
-  // the target branch is a direct descendant of the base branch
-  // which means the target branch is already up to date and the commits
-  // do not need to be applied
-  const isDirectDescendant = base === baseBranch.tip.sha
-  const commitsOrIgnore = isDirectDescendant ? [] : commits
-
   onUpdate({
     kind: ComputedAction.Clean,
-    commits: commitsOrIgnore,
+    commits,
   })
 }