fix: introduce file cache to simplify fetching files including file mode

src/errors/index.ts

@@ -51,6 +51,7 @@ export class GitHubAPIError extends Error {
     this.body = GitHubAPIError.parseErrorBody(requestError);
     this.name = GitHubAPIError.name;
     this.cause = requestError;
+    this.stack = requestError.stack;
   }
 
   static parseErrorBody(
@@ -81,3 +82,12 @@ export class DuplicateReleaseError extends GitHubAPIError {
     this.name = DuplicateReleaseError.name;
   }
 }
+
+export class FileNotFoundError extends Error {
+  path: string;
+  constructor(path: string) {
+    super(`Failed to find file: ${path}`);
+    this.path = path;
+    this.name = FileNotFoundError.name;
+  }
+}

src/github.ts

@@ -34,12 +34,16 @@ import {Update} from './update';
 import {Release} from './release';
 import {ROOT_PROJECT_PATH} from './manifest';
 import {signoffCommitMessage} from './util/signoff-commit-message';
+import {
+  RepositoryFileCache,
+  GitHubFileContents,
+  DEFAULT_FILE_MODE,
+} from './util/file-cache';
 
 // Extract some types from the `request` package.
 type RequestBuilderType = typeof request;
 type DefaultFunctionType = RequestBuilderType['defaults'];
 type RequestFunctionType = ReturnType<DefaultFunctionType>;
-type RequestOptionsType = Parameters<DefaultFunctionType>[0];
 export interface OctokitAPIs {
   graphql: Function;
   request: RequestFunctionType;
@@ -61,12 +65,6 @@ interface GitHubCreateOptions {
   token?: string;
 }
 
-export interface GitHubFileContents {
-  sha: string;
-  content: string;
-  parsedContent: string;
-}
-
 type CommitFilter = (commit: Commit) => boolean;
 
 interface GraphQLCommit {
@@ -176,12 +174,14 @@ export class GitHub {
   private octokit: OctokitType;
   private request: RequestFunctionType;
   private graphql: Function;
+  private fileCache: RepositoryFileCache;
 
   private constructor(options: GitHubOptions) {
     this.repository = options.repository;
     this.octokit = options.octokitAPIs.octokit;
     this.request = options.octokitAPIs.request;
     this.graphql = options.octokitAPIs.graphql;
+    this.fileCache = new RepositoryFileCache(this.octokit, this.repository);
   }
 
   /**
@@ -754,80 +754,6 @@ export class GitHub {
     );
   }
 
-  /**
-   * Fetch the contents of a file with the Contents API
-   *
-   * @param {string} path The path to the file in the repository
-   * @param {string} branch The branch to fetch from
-   * @returns {GitHubFileContents}
-   * @throws {GitHubAPIError} on other API errors
-   */
-  getFileContentsWithSimpleAPI = wrapAsync(
-    async (
-      path: string,
-      ref: string,
-      isBranch = true
-    ): Promise<GitHubFileContents> => {
-      ref = isBranch ? fullyQualifyBranchRef(ref) : ref;
-      const options: RequestOptionsType = {
-        owner: this.repository.owner,
-        repo: this.repository.repo,
-        path,
-        ref,
-      };
-      const resp = await this.request(
-        'GET /repos/:owner/:repo/contents/:path',
-        options
-      );
-      return {
-        parsedContent: Buffer.from(resp.data.content, 'base64').toString(
-          'utf8'
-        ),
-        content: resp.data.content,
-        sha: resp.data.sha,
-      };
-    }
-  );
-
-  /**
-   * Fetch the contents of a file using the Git data API
-   *
-   * @param {string} path The path to the file in the repository
-   * @param {string} branch The branch to fetch from
-   * @returns {GitHubFileContents}
-   * @throws {GitHubAPIError} on other API errors
-   */
-  getFileContentsWithDataAPI = wrapAsync(
-    async (path: string, branch: string): Promise<GitHubFileContents> => {
-      const repoTree = await this.octokit.git.getTree({
-        owner: this.repository.owner,
-        repo: this.repository.repo,
-        tree_sha: branch,
-      });
-
-      const blobDescriptor = repoTree.data.tree.find(
-        tree => tree.path === path
-      );
-      if (!blobDescriptor) {
-        throw new Error(`Could not find requested path: ${path}`);
-      }
-
-      const resp = await this.octokit.git.getBlob({
-        owner: this.repository.owner,
-        repo: this.repository.repo,
-        file_sha: blobDescriptor.sha!,
-      });
-
-      return {
-        parsedContent: Buffer.from(resp.data.content, 'base64').toString(
-          'utf8'
-        ),
-        content: resp.data.content,
-        sha: resp.data.sha,
-      };
-    }
-  );
-
   /**
    * Fetch the contents of a file
    *
@@ -841,14 +767,7 @@ export class GitHub {
     branch: string
   ): Promise<GitHubFileContents> {
     logger.debug(`Fetching ${path} from branch ${branch}`);
-    try {
-      return await this.getFileContentsWithSimpleAPI(path, branch);
-    } catch (err) {
-      if (err.status === 403) {
-        return await this.getFileContentsWithDataAPI(path, branch);
-      }
-      throw err;
-    }
+    return await this.fileCache.getFileContents(path, branch);
   }
 
   async getFileJson<T>(path: string, branch: string): Promise<T> {
@@ -1108,19 +1027,12 @@ export class GitHub {
   ): Promise<Changes> {
     const changes = new Map();
     for (const update of updates) {
-      let content;
+      let content: GitHubFileContents | undefined;
       try {
-        if (update.cachedFileContents) {
-          // we already loaded the file contents earlier, let's not
-          // hit GitHub again.
-          content = {data: update.cachedFileContents};
-        } else {
-          const fileContent = await this.getFileContentsOnBranch(
-            update.path,
-            defaultBranch
-          );
-          content = {data: fileContent};
-        }
+        content = await this.getFileContentsOnBranch(
+          update.path,
+          defaultBranch
+        );
       } catch (err) {
         if (err.status !== 404) throw err;
         // if the file is missing and create = false, just continue
@@ -1131,13 +1043,13 @@ export class GitHub {
         }
       }
       const contentText = content
-        ? Buffer.from(content.data.content, 'base64').toString('utf8')
+        ? Buffer.from(content.content, 'base64').toString('utf8')
         : undefined;
       const updatedContent = update.updater.updateContent(contentText);
       if (updatedContent) {
         changes.set(update.path, {
           content: updatedContent,
-          mode: '100644',
+          mode: content?.mode || DEFAULT_FILE_MODE,
         });
       }
     }
@@ -1361,19 +1273,6 @@ export class GitHub {
   }
 }
 
-// Takes a potentially unqualified branch name, and turns it
-// into a fully qualified ref.
-//
-// e.g. main -> refs/heads/main
-function fullyQualifyBranchRef(refName: string): string {
-  let final = refName;
-  if (final.indexOf('/') < 0) {
-    final = `refs/heads/${final}`;
-  }
-
-  return final;
-}
-
 /**
  * Normalize a provided prefix by removing leading and trailing
  * slashes.

src/strategies/dart.ts

@@ -19,7 +19,7 @@ import * as yaml from 'js-yaml';
 // pubspec
 import {PubspecYaml} from '../updaters/dart/pubspec-yaml';
 import {BaseStrategy, BuildUpdatesOptions} from './base';
-import {GitHubFileContents} from '../github';
+import {GitHubFileContents} from '../util/file-cache';
 import {Update} from '../update';
 
 export class Dart extends BaseStrategy {

src/strategies/helm.ts

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-import {GitHubFileContents} from '../github';
+import {GitHubFileContents} from '../util/file-cache';
 
 // Generic
 import {Changelog} from '../updaters/changelog';

src/strategies/java-yoshi.ts

@@ -18,7 +18,7 @@ import {Version, VersionsMap} from '../version';
 import {JavaUpdate} from '../updaters/java/java-update';
 import {BaseStrategy, BuildUpdatesOptions, BaseStrategyOptions} from './base';
 import {Changelog} from '../updaters/changelog';
-import {GitHubFileContents} from '../github';
+import {GitHubFileContents} from '../util/file-cache';
 import {JavaSnapshot} from '../versioning-strategies/java-snapshot';
 import {GitHubAPIError, MissingRequiredFileError} from '../errors';
 import {Commit, ConventionalCommit} from '../commit';

src/strategies/krm-blueprint.ts

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-import {GitHubFileContents} from '../github';
+import {GitHubFileContents} from '../util/file-cache';
 
 // Generic
 import {Changelog} from '../updaters/changelog';

src/strategies/node.ts

@@ -18,7 +18,7 @@ import {PackageLockJson} from '../updaters/node/package-lock-json';
 import {SamplesPackageJson} from '../updaters/node/samples-package-json';
 import {Changelog} from '../updaters/changelog';
 import {PackageJson} from '../updaters/node/package-json';
-import {GitHubFileContents} from '../github';
+import {GitHubFileContents} from '../util/file-cache';
 
 export class Node extends BaseStrategy {
   private pkgJsonContents?: GitHubFileContents;

src/strategies/ocaml.ts

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-import {GitHubFileContents} from '../github';
+import {GitHubFileContents} from '../util/file-cache';
 
 // Generic
 import {Changelog} from '../updaters/changelog';

src/strategies/php-yoshi.ts

@@ -29,7 +29,7 @@ import {TagName} from '../util/tag-name';
 import {PullRequestTitle} from '../util/pull-request-title';
 import {BranchName} from '../util/branch-name';
 import {PullRequestBody} from '../util/pull-request-body';
-import {GitHubFileContents} from '../github';
+import {GitHubFileContents} from '../util/file-cache';
 
 const CHANGELOG_SECTIONS = [
   {type: 'feat', section: 'Features'},

src/strategies/rust.ts

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-import {GitHubFileContents} from '../github';
+import {GitHubFileContents} from '../util/file-cache';
 
 // Generic
 import {Changelog} from '../updaters/changelog';

src/update.ts

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-import {GitHubFileContents} from './github';
+import {GitHubFileContents} from './util/file-cache';
 
 /**
  * An update is a collection of data that represents changes to