Add patch prep code to avoid broken states upon merge conflict errors

Signed-off-by: Erik Engervall <erik.engervall@gmail.com>

plugins/git-release-manager/src/features/Patch/hooks/usePatch.ts

@@ -15,7 +15,7 @@
  */
 
 import { useEffect, useState } from 'react';
-import { useAsync, useAsyncFn } from 'react-use';
+import { useAsync } from 'react-use';
 import {
   GetLatestReleaseResult,
   GetRecentCommitsResultSingle,
@@ -32,9 +32,9 @@ import { gitReleaseManagerApiRef } from '../../../api/serviceApiRef';
 import { Project } from '../../../contexts/ProjectContext';
 import { SemverTagParts } from '../../../helpers/tagParts/getSemverTagParts';
 import { TAG_OBJECT_MESSAGE } from '../../../constants/constants';
-import { useResponseSteps } from '../../../hooks/useResponseSteps';
 import { useUserContext } from '../../../contexts/UserContext';
 import { useApi } from '@backstage/core-plugin-api';
+import { usePatchPreparation } from './usePatchPrep';
 
 export interface UsePatch {
   bumpedTag: string;
@@ -54,38 +54,53 @@ export function usePatch({
 }: UsePatch): CardHook<GetRecentCommitsResultSingle> {
   const pluginApiClient = useApi(gitReleaseManagerApiRef);
   const { user } = useUserContext();
-  const { responseSteps, addStepToResponseSteps, asyncCatcher, abortIfError } =
-    useResponseSteps();
 
   const releaseBranchName = latestRelease.targetCommitish;
 
+  const {
+    run,
+    runInvoked,
+    lastCallRes,
+    abortIfError,
+    addStepToResponseSteps,
+    asyncCatcher,
+    responseSteps,
+    TOTAL_PATCH_PREP_STEPS,
+    selectedPatchCommit,
+  } = usePatchPreparation({
+    bumpedTag,
+    releaseBranchName,
+    project,
+    tagParts,
+  });
+
   /**
    * (1) Here is the branch we want to cherry-pick to:
    * > branch = GET /repos/$owner/$repo/branches/$branchName
    * > branchSha = branch.commit.sha
    * > branchTree = branch.commit.commit.tree.sha
    */
-  const [releaseBranchRes, run] = useAsyncFn(
-    async (selectedPatchCommit: GetRecentCommitsResultSingle) => {
-      const { branch: releaseBranch } = await pluginApiClient
-        .getBranch({
-          owner: project.owner,
-          repo: project.repo,
-          branch: releaseBranchName,
-        })
-        .catch(asyncCatcher);
+  const releaseBranchRes = useAsync(async () => {
+    abortIfError(lastCallRes.error);
+    if (!lastCallRes.value) return undefined;
 
-      addStepToResponseSteps({
-        message: `Fetched release branch "${releaseBranch.name}"`,
-        link: releaseBranch.links.html,
-      });
+    const { branch: releaseBranch } = await pluginApiClient
+      .getBranch({
+        owner: project.owner,
+        repo: project.repo,
+        branch: releaseBranchName,
+      })
+      .catch(asyncCatcher);
 
-      return {
-        releaseBranch,
-        selectedPatchCommit,
-      };
-    },
-  );
+    addStepToResponseSteps({
+      message: `Fetched release branch "${releaseBranch.name}"`,
+      link: releaseBranch.links.html,
+    });
+
+    return {
+      releaseBranch,
+    };
+  }, [lastCallRes.value, lastCallRes.error]);
 
   /**
    *  (2) Create a temporary commit on the branch, which extends as a sibling of
@@ -102,9 +117,7 @@ export function usePatch({
         owner: project.owner,
         repo: project.repo,
         message: `Temporary commit for patch ${tagParts.patch}`,
-        parents: [
-          releaseBranchRes.value.selectedPatchCommit.firstParentSha ?? '',
-        ],
+        parents: [selectedPatchCommit.firstParentSha ?? ''],
         tree: releaseBranchRes.value.releaseBranch.commit.commit.tree.sha,
       })
       .catch(asyncCatcher);
@@ -159,7 +172,7 @@ export function usePatch({
         owner: project.owner,
         repo: project.repo,
         base: releaseBranchName,
-        head: releaseBranchRes.value.selectedPatchCommit.sha,
+        head: selectedPatchCommit.sha,
       })
       .catch(asyncCatcher);
 
@@ -184,7 +197,6 @@ export function usePatch({
     if (!mergeRes.value || !releaseBranchRes.value) return undefined;
 
     const releaseBranchSha = releaseBranchRes.value.releaseBranch.commit.sha;
-    const selectedPatchCommit = releaseBranchRes.value.selectedPatchCommit;
 
     const { commit: cherryPickCommit } = await pluginApiClient.createCommit({
       owner: project.owner,
@@ -299,8 +311,6 @@ export function usePatch({
     abortIfError(createdReferenceRes.error);
     if (!createdReferenceRes.value || !releaseBranchRes.value) return undefined;
 
-    const selectedPatchCommit = releaseBranchRes.value.selectedPatchCommit;
-
     const { release } = await pluginApiClient
       .updateRelease({
         owner: project.owner,
@@ -343,16 +353,15 @@ ${selectedPatchCommit.commit.message}`,
           project,
           tagParts,
         },
-        patchCommitMessage:
-          releaseBranchRes.value.selectedPatchCommit.commit.message,
-        patchCommitUrl: releaseBranchRes.value.selectedPatchCommit.htmlUrl,
+        patchCommitMessage: selectedPatchCommit.commit.message,
+        patchCommitUrl: selectedPatchCommit.htmlUrl,
         patchedTag: updatedReleaseRes.value.tagName,
         previousTag: latestRelease.tagName,
         updatedReleaseName: updatedReleaseRes.value.name,
         updatedReleaseUrl: updatedReleaseRes.value.htmlUrl,
       });
     } catch (error) {
-      asyncCatcher(error);
+      asyncCatcher(error as Error);
     }
 
     addStepToResponseSteps({
@@ -361,7 +370,7 @@ ${selectedPatchCommit.commit.message}`,
     });
   }, [updatedReleaseRes.value, updatedReleaseRes.error]);
 
-  const TOTAL_STEPS = 9 + (!!onSuccess ? 1 : 0);
+  const TOTAL_STEPS = 9 + (!!onSuccess ? 1 : 0) + TOTAL_PATCH_PREP_STEPS;
   const [progress, setProgress] = useState(0);
   useEffect(() => {
     setProgress((responseSteps.length / TOTAL_STEPS) * 100);
@@ -371,10 +380,6 @@ ${selectedPatchCommit.commit.message}`,
     progress,
     responseSteps,
     run,
-    runInvoked: Boolean(
-      releaseBranchRes.loading ||
-        releaseBranchRes.value ||
-        releaseBranchRes.error,
-    ),
+    runInvoked,
   };
 }

plugins/git-release-manager/src/features/Patch/hooks/usePatchPrep.ts

@@ -0,0 +1,335 @@
+/*
+ * Copyright 2021 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { useAsync, useAsyncFn } from 'react-use';
+import { useApi } from '@backstage/core-plugin-api';
+
+import { GetRecentCommitsResultSingle } from '../../../api/GitReleaseClient';
+import { CalverTagParts } from '../../../helpers/tagParts/getCalverTagParts';
+import { getPatchCommitSuffix } from '../helpers/getPatchCommitSuffix';
+import { gitReleaseManagerApiRef } from '../../../api/serviceApiRef';
+import { GitReleaseManagerError } from '../../../errors/GitReleaseManagerError';
+import { Project } from '../../../contexts/ProjectContext';
+import { SemverTagParts } from '../../../helpers/tagParts/getSemverTagParts';
+import { useResponseSteps } from '../../../hooks/useResponseSteps';
+
+export interface UsePatchPreparation {
+  bumpedTag: string;
+  releaseBranchName: string;
+  project: Project;
+  tagParts: NonNullable<CalverTagParts | SemverTagParts>;
+}
+
+// Inspiration: https://stackoverflow.com/questions/53859199/how-to-cherry-pick-through-githubs-api
+export function usePatchPreparation({
+  bumpedTag,
+  releaseBranchName,
+  project,
+  tagParts,
+}: UsePatchPreparation) {
+  const pluginApiClient = useApi(gitReleaseManagerApiRef);
+  const { responseSteps, addStepToResponseSteps, asyncCatcher, abortIfError } =
+    useResponseSteps();
+
+  const tempPatchBranchName = `${releaseBranchName}-temp-patch-prep`;
+
+  /**
+   * (1) Get the release branch's most recent commit
+   */
+  const [latestCommitOnReleaseBranchRes, run] = useAsyncFn(
+    async (selectedPatchCommit: GetRecentCommitsResultSingle) => {
+      const { commit: latestCommit } = await pluginApiClient
+        .getCommit({
+          owner: project.owner,
+          repo: project.repo,
+          ref: releaseBranchName,
+        })
+        .catch(asyncCatcher);
+
+      addStepToResponseSteps({
+        message: `[patch prep] Fetched latest commit from "${releaseBranchName}"`,
+        secondaryMessage: `with message "${latestCommit.commit.message}"`,
+        link: latestCommit.htmlUrl,
+      });
+
+      return {
+        latestCommit,
+        selectedPatchCommit,
+      };
+    },
+  );
+
+  /**
+   * (2) Create temporary patch branch based on release branch's most recent sha
+   * to test if programmatic cherry pick patching is possible
+   */
+  const createTempPatchBranchRes = useAsync(async () => {
+    abortIfError(latestCommitOnReleaseBranchRes.error);
+    if (!latestCommitOnReleaseBranchRes.value) return undefined;
+
+    const { reference: createdReleaseBranch } = await pluginApiClient
+      .createRef({
+        owner: project.owner,
+        repo: project.repo,
+        sha: latestCommitOnReleaseBranchRes.value.latestCommit.sha,
+        ref: `refs/heads/${tempPatchBranchName}`,
+      })
+      .catch(error => {
+        if (error?.body?.message === 'Reference already exists') {
+          throw new GitReleaseManagerError(
+            `Branch "${tempPatchBranchName}" already exists: .../tree/${tempPatchBranchName}`,
+          );
+        }
+        throw error;
+      })
+      .catch(asyncCatcher);
+
+    addStepToResponseSteps({
+      message: '[patch prep] Created Temp Patch Branch',
+      secondaryMessage: `with ref "${createdReleaseBranch.ref}"`,
+    });
+
+    return {
+      ...createdReleaseBranch,
+      selectedPatchCommit:
+        latestCommitOnReleaseBranchRes.value.selectedPatchCommit,
+    };
+  }, [
+    latestCommitOnReleaseBranchRes.value,
+    latestCommitOnReleaseBranchRes.error,
+  ]);
+
+  /**
+   * (3) Here is the branch we want to cherry-pick to:
+   * > branch = GET /repos/$owner/$repo/branches/$branchName
+   * > branchSha = branch.commit.sha
+   * > branchTree = branch.commit.commit.tree.sha
+   */
+  const tempPatchBranchRes = useAsync(async () => {
+    abortIfError(createTempPatchBranchRes.error);
+    if (!createTempPatchBranchRes.value) return undefined;
+
+    const { branch: releaseBranch } = await pluginApiClient
+      .getBranch({
+        owner: project.owner,
+        repo: project.repo,
+        branch: tempPatchBranchName,
+      })
+      .catch(asyncCatcher);
+
+    addStepToResponseSteps({
+      message: `[patch prep] Fetched release branch "${releaseBranch.name}"`,
+      link: releaseBranch.links.html,
+    });
+
+    return {
+      releaseBranch,
+      selectedPatchCommit: createTempPatchBranchRes.value.selectedPatchCommit,
+    };
+  }, [createTempPatchBranchRes.value, createTempPatchBranchRes.error]);
+
+  /**
+   *  (4) Create a temporary commit on the branch, which extends as a sibling of
+   *  the commit we want but contains the current tree of the target branch:
+   *  > parentSha = commit.parents.head // first parent -- there should only be one
+   *  > tempCommit = POST /repos/$owner/$repo/git/commits { "message": "temp", "tree": branchTree, "parents": [parentSha] }
+   */
+  const tempCommitRes = useAsync(async () => {
+    abortIfError(tempPatchBranchRes.error);
+    if (!tempPatchBranchRes.value) return undefined;
+
+    const { commit: tempCommit } = await pluginApiClient
+      .createCommit({
+        owner: project.owner,
+        repo: project.repo,
+        message: `[patch prep] Temporary commit for patch ${tagParts.patch}`,
+        parents: [
+          tempPatchBranchRes.value.selectedPatchCommit.firstParentSha ?? '',
+        ],
+        tree: tempPatchBranchRes.value.releaseBranch.commit.commit.tree.sha,
+      })
+      .catch(asyncCatcher);
+
+    addStepToResponseSteps({
+      message: '[patch prep] Created temporary commit',
+      secondaryMessage: `with message "${tempCommit.message}"`,
+    });
+
+    return {
+      ...tempCommit,
+    };
+  }, [tempPatchBranchRes.value, tempPatchBranchRes.error]);
+
+  /**
+   * (5) Now temporarily force the branch over to that commit:
+   * > PATCH /repos/$owner/$repo/git/refs/heads/$refName { sha = tempCommit.sha, force = true }
+   */
+  const forceBranchRes = useAsync(async () => {
+    abortIfError(tempCommitRes.error);
+    if (!tempCommitRes.value) return undefined;
+
+    await pluginApiClient
+      .updateRef({
+        owner: project.owner,
+        repo: project.repo,
+        sha: tempCommitRes.value.sha,
+        ref: `heads/${tempPatchBranchName}`,
+        force: true,
+      })
+      .catch(asyncCatcher);
+
+    addStepToResponseSteps({
+      message: `[patch prep] Forced branch "${tempPatchBranchName}" to temporary commit "${tempCommitRes.value.sha}"`,
+    });
+
+    return {
+      trigger: 'next step 🚀 ',
+    };
+  }, [tempCommitRes.value, tempCommitRes.error]);
+
+  /**
+   * (6) Merge the commit we want into this mess:
+   * > merge = POST /repos/$owner/$repo/merges { "base": branchName, "head": commit.sha }
+   */
+  const mergeRes = useAsync(async () => {
+    abortIfError(forceBranchRes.error);
+    if (!forceBranchRes.value || !tempPatchBranchRes.value) return undefined;
+
+    const { merge } = await pluginApiClient
+      .merge({
+        owner: project.owner,
+        repo: project.repo,
+        base: tempPatchBranchName,
+        head: tempPatchBranchRes.value.selectedPatchCommit.sha,
+      })
+      .catch(asyncCatcher);
+
+    addStepToResponseSteps({
+      message: `[patch prep] Merged temporary commit into "${tempPatchBranchName}"`,
+      secondaryMessage: `with message "${merge.commit.message}"`,
+      link: merge.htmlUrl,
+    });
+
+    return {
+      ...merge,
+    };
+  }, [forceBranchRes.value, forceBranchRes.error]);
+
+  /**
+   * (7) Now that we know what the tree should be, create the cherry-pick commit.
+   * Note that branchSha is the original from up at the top.
+   * > cherry = POST /repos/$owner/$repo/git/commits { "message": "looks good!", "tree": mergeTree, "parents": [branchSha] }
+   */
+  const cherryPickRes = useAsync(async () => {
+    abortIfError(mergeRes.error);
+    if (!mergeRes.value || !tempPatchBranchRes.value) return undefined;
+
+    const releaseBranchSha = tempPatchBranchRes.value.releaseBranch.commit.sha;
+    const selectedPatchCommit = tempPatchBranchRes.value.selectedPatchCommit;
+
+    const { commit: cherryPickCommit } = await pluginApiClient.createCommit({
+      owner: project.owner,
+      repo: project.repo,
+      message: `[patch prep] [patch ${bumpedTag}] ${
+        selectedPatchCommit.commit.message
+      }
+
+      ${getPatchCommitSuffix({
+        commitSha: selectedPatchCommit.sha,
+      })}`,
+      parents: [releaseBranchSha],
+      tree: mergeRes.value.commit.tree.sha,
+    });
+
+    addStepToResponseSteps({
+      message: `[patch prep] Cherry-picked patch commit to "${releaseBranchSha}"`,
+      secondaryMessage: `with message "${cherryPickCommit.message}"`,
+    });
+
+    return {
+      ...cherryPickCommit,
+    };
+  }, [mergeRes.value, mergeRes.error]);
+
+  /**
+   * (8) Replace the temp commit with the real commit:
+   * > PATCH /repos/$owner/$repo/git/refs/heads/$refName { sha = cherry.sha, force = true }
+   */
+  const updatedRefRes = useAsync(async () => {
+    abortIfError(cherryPickRes.error);
+    if (!cherryPickRes.value) return undefined;
+
+    const { reference: updatedReference } = await pluginApiClient
+      .updateRef({
+        owner: project.owner,
+        repo: project.repo,
+        ref: `heads/${tempPatchBranchName}`,
+        sha: cherryPickRes.value.sha,
+        force: true,
+      })
+      .catch(asyncCatcher);
+
+    addStepToResponseSteps({
+      message: `[patch prep] Updated reference "${updatedReference.ref}"`,
+    });
+
+    return {
+      ...updatedReference,
+    };
+  }, [cherryPickRes.value, cherryPickRes.error]);
+
+  /**
+   * (9) Delete temp patch branch
+   */
+  const deleteTempPatchBranchRes = useAsync(async () => {
+    abortIfError(cherryPickRes.error);
+    if (!cherryPickRes.value) return undefined;
+
+    const { success: deletedReferenceSuccess } =
+      await pluginApiClient.deleteRef({
+        owner: project.owner,
+        repo: project.repo,
+        ref: `heads/${tempPatchBranchName}`,
+      });
+
+    addStepToResponseSteps({
+      message: `[patch prep] Deleted temporary patch prep branch "${tempPatchBranchName}"`,
+    });
+
+    return {
+      deletedReferenceSuccess,
+    };
+  }, [updatedRefRes.value, updatedRefRes.error]);
+
+  const TOTAL_PATCH_PREP_STEPS = 9;
+
+  return {
+    TOTAL_PATCH_PREP_STEPS,
+    run,
+    runInvoked: Boolean(
+      deleteTempPatchBranchRes.loading ||
+        deleteTempPatchBranchRes.value ||
+        deleteTempPatchBranchRes.error,
+    ),
+    lastCallRes: deleteTempPatchBranchRes,
+    responseSteps,
+    addStepToResponseSteps,
+    asyncCatcher,
+    abortIfError,
+    selectedPatchCommit: latestCommitOnReleaseBranchRes.value
+      ?.selectedPatchCommit as any,
+  };
+}