Merge pull request desktop#11549 from desktop/cherry-pick-git-no-conf…

…ict-resolution

Cherry pick git no confict resolution

app/src/lib/git/cherry-pick.ts

@@ -0,0 +1,47 @@
+import { Repository } from '../../models/repository'
+import { git, IGitResult } from './core'
+
+/** The app-specific results from attempting to cherry pick commits*/
+export enum CherryPickResult {
+  /**
+   * Git completed the cherry pick without reporting any errors, and the caller can
+   * signal success to the user.
+   */
+  CompletedWithoutError = 'CompletedWithoutError',
+
+  /**
+   * An unexpected error as part of the cherry pick flow was caught and handled.
+   *
+   * Check the logs to find the relevant Git details.
+   */
+  Error = 'Error',
+}
+
+/**
+ * A stub function to initiate cherry picking in the app.
+ *
+ * @param revisionRange - this could be a single commit sha or could be a range
+ * of commits like sha1..sha2 or inclusively sha1^..sha2
+ */
+export async function cherryPick(
+  repository: Repository,
+  revisionRange: string
+): Promise<CherryPickResult> {
+  const result = await git(
+    ['cherry-pick', revisionRange],
+    repository.path,
+    'cherry pick'
+  )
+
+  return parseCherryPickResult(result)
+}
+
+function parseCherryPickResult(result: IGitResult): CherryPickResult {
+  if (result.exitCode === 0) {
+    return CherryPickResult.CompletedWithoutError
+  }
+
+  // TODO: handle known exceptions
+
+  throw new Error(`Unhandled result found: '${JSON.stringify(result)}'`)
+}

app/src/lib/git/rev-list.ts

@@ -7,7 +7,8 @@ import { CommitOneLine } from '../../models/commit'
 /**
  * Convert two refs into the Git range syntax representing the set of commits
  * that are reachable from `to` but excluding those that are reachable from
- * `from`.
+ * `from`. This will not be inclusive to the `from` ref, see
+ * `revRangeInclusive`.
  *
  * Each parameter can be the commit SHA or a ref name, or specify an empty
  * string to represent HEAD.
@@ -19,6 +20,21 @@ export function revRange(from: string, to: string) {
   return `${from}..${to}`
 }
 
+/**
+ * Convert two refs into the Git range syntax representing the set of commits
+ * that are reachable from `to` but excluding those that are reachable from
+ * `from`. However as opposed to `revRange`, this will also include `from` ref.
+ *
+ * Each parameter can be the commit SHA or a ref name, or specify an empty
+ * string to represent HEAD.
+ *
+ * @param from The start of the range
+ * @param to The end of the range
+ */
+export function revRangeInclusive(from: string, to: string) {
+  return `${from}^..${to}`
+}
+
 /**
  * Convert two refs into the Git symmetric difference syntax, which represents
  * the set of commits that are reachable from either `from` or `to` but not

app/test/helpers/repositories.ts

@@ -62,6 +62,19 @@ export async function setupEmptyRepository(): Promise<Repository> {
   return new Repository(repoPath, -1, null, false)
 }
 
+/**
+ * Initializes a new, empty, git repository at in a temporary location with
+ * default branch of main.
+ *
+ * @returns the new local repository
+ */
+export async function setupEmptyRepositoryDefaultMain(): Promise<Repository> {
+  const repoPath = mkdirSync('desktop-empty-repo-')
+  await GitProcess.exec(['init', '-b', 'main'], repoPath)
+
+  return new Repository(repoPath, -1, null, false)
+}
+
 /**
  * Initialize a new, empty folder that is incorrectly associated with a Git
  * repository. This should only be used to test error handling of the Git

app/test/helpers/repository-builder-cherry-pick-test.ts

@@ -0,0 +1,45 @@
+import { Repository } from '../../src/models/repository'
+import { setupEmptyRepositoryDefaultMain } from './repositories'
+import { makeCommit, switchTo, createBranch } from './repository-scaffolding'
+
+/**
+ * Creates a test repository to be used for testing cherry pick behaviour with:
+ *  - one commit on default branch,
+ *  - one commit on `featureBranchName` to cherry pick
+ *  - creates `targetBranchName` off of default branch
+ */
+export async function createRepository(
+  featureBranchName: string,
+  targetBranchName: string
+): Promise<Repository> {
+  const repository = await setupEmptyRepositoryDefaultMain()
+
+  const firstCommit = {
+    commitMessage: 'First!',
+    entries: [
+      {
+        path: 'README.md',
+        contents: '# HELLO WORLD! \n',
+      },
+    ],
+  }
+  await makeCommit(repository, firstCommit)
+
+  await createBranch(repository, featureBranchName, 'HEAD')
+  await createBranch(repository, targetBranchName, 'HEAD')
+
+  await switchTo(repository, featureBranchName)
+  const featureBranchCommit = {
+    commitMessage: 'Cherry Picked Feature!',
+    entries: [
+      {
+        path: 'THING.md',
+        contents: '# HELLO WORLD! \nTHINGS GO HERE\n',
+      },
+    ],
+  }
+  await makeCommit(repository, featureBranchCommit)
+
+  await switchTo(repository, targetBranchName)
+  return repository
+}