refactor: simplify git helpers (#134)

Author: tjkandala

.vscode/tasks.json

@@ -9,5 +9,10 @@
         "reveal": "never",
       },
     },
+    {
+      "type": "npm",
+      "script": "build",
+      "label": "build",
+    },
   ],
 }

src/extension.ts

@@ -31,10 +31,11 @@ async function openCommand(): Promise<void> {
     if (!editor) {
         throw new Error('No active editor')
     }
-    const [remoteURL, branch, fileRelative] = await repoInfo(editor.document.uri.fsPath)
-    if (remoteURL === '') {
+    const repositoryInfo = await repoInfo(editor.document.uri.fsPath)
+    if (!repositoryInfo) {
         return
     }
+    const { remoteURL, branch, fileRelative } = repositoryInfo
 
     // Open in browser.
     await open(
@@ -59,7 +60,11 @@ async function searchCommand(): Promise<void> {
     if (!editor) {
         throw new Error('No active editor')
     }
-    const [remoteURL, branch, fileRelative] = await repoInfo(editor.document.uri.fsPath)
+    const repositoryInfo = await repoInfo(editor.document.uri.fsPath)
+    if (!repositoryInfo) {
+        return
+    }
+    const { remoteURL, branch, fileRelative } = repositoryInfo
 
     const query = editor.document.getText(editor.selection)
     if (query === '') {

src/git.ts

@@ -4,26 +4,12 @@ import { log } from './log'
 import { getRemoteUrlReplacements } from './config'
 
 /**
- * Returns [remote, upstream branch].
- * Empty remote is returned if the upstream branch points to a local branch.
- * Empty upstream branch is returned if there is no upstream branch.
+ * Returns the repository root directory for any directory within the
+ * repository.
  */
-async function gitRemoteBranch(repoDirectory: string): Promise<[string, string]> {
-    try {
-        const { stdout } = await execa('git', ['rev-parse', '--abbrev-ref', 'HEAD@{upstream}'], { cwd: repoDirectory })
-        const remoteAndBranch = stdout.split('/')
-        if (remoteAndBranch.length === 2) {
-            const [remote, branch] = remoteAndBranch
-            return [remote, branch]
-        }
-        if (remoteAndBranch.length === 1) {
-            // The upstream branch points to a local branch.
-            return ['', remoteAndBranch[0]]
-        }
-        return ['', '']
-    } catch {
-        return ['', '']
-    }
+async function gitRootDirectory(repoDirectory: string): Promise<string> {
+    const { stdout } = await execa('git', ['rev-parse', '--show-toplevel'], { cwd: repoDirectory })
+    return stdout
 }
 
 /**
@@ -51,74 +37,92 @@ async function gitRemoteURL(repoDirectory: string, remoteName: string): Promise<
     return stdout
 }
 
+interface RemoteName {
+    /**
+     * Remote name of the upstream repository,
+     * or the first found remote name if no upstream is found
+     */
+    remoteName: string
+}
+
+interface Branch {
+    /**
+     * Remote branch name, or 'HEAD' if it isn't found because
+     * e.g. detached HEAD state, upstream branch points to a local branch
+     */
+    branch: string
+}
+
 /**
- * Returns the remote URL.
+ * Returns the remote name and branch
+ *
+ * @param repoDirectory the repository root directory
  */
-async function gitDefaultRemoteURL(repoDirectory: string): Promise<string> {
-    const [remote] = await gitRemoteBranch(repoDirectory)
-    if (remote !== '') {
-        return gitRemoteURL(repoDirectory, remote)
+async function gitRemoteNameAndBranch(repoDirectory: string): Promise<RemoteName & Branch> {
+    let remoteName: string | undefined
+    let branch = 'HEAD'
+
+    const { stdout } = await execa('git', ['rev-parse', '--abbrev-ref', 'HEAD@{upstream}'], { cwd: repoDirectory })
+    const remoteAndBranch = stdout.split('/')
+
+    if (remoteAndBranch.length === 1) {
+        // The upstream branch points to a local branch.
+        ;[remoteName] = remoteAndBranch
+    }
+    if (remoteAndBranch.length === 2) {
+        ;[remoteName, branch] = remoteAndBranch
     }
 
     // If we cannot find the remote name deterministically, we use the first
     // Git remote found.
-    const remotes = await gitRemotes(repoDirectory)
-    if (remotes.length === 0) {
-        throw new Error('no configured git remotes')
+    if (!remoteName) {
+        const remotes = await gitRemotes(repoDirectory)
+        if (remotes.length > 1) {
+            log.appendLine(`using first git remote: ${remotes[0]}`)
+            remoteName = remotes[0]
+        }
     }
-    if (remotes.length > 1) {
-        log.appendLine(`using first git remote: ${remotes[0]}`)
+
+    // Throw if a remote still isn't found
+    if (!remoteName) {
+        throw new Error('no configured git remotes')
     }
-    return gitRemoteURL(repoDirectory, remotes[0])
-}
 
-/**
- * Returns the repository root directory for any directory within the
- * repository.
- */
-async function gitRootDirectory(repoDirectory: string): Promise<string> {
-    const { stdout } = await execa('git', ['rev-parse', '--show-toplevel'], { cwd: repoDirectory })
-    return stdout
+    return { remoteName, branch }
 }
 
-/**
- * Returns either the current remote branch name of the repository OR in all
- * other cases (e.g. detached HEAD state, upstream branch points to a local
- * branch), it returns "HEAD".
- */
-async function gitBranch(repoDirectory: string): Promise<string> {
-    const [origin, branch] = await gitRemoteBranch(repoDirectory)
-    if (origin !== '') {
-        // The remote branch exists.
-        return branch
-    }
-    return 'HEAD'
+interface RepositoryInfo extends Branch {
+    /** Git repository remote URL */
+    remoteURL: string
+
+    /** File path relative to the repository root */
+    fileRelative: string
 }
 
 /**
  * Returns the Git repository remote URL, the current branch, and the file path
- * relative to the repository root. Empty strings are returned if this cannot be
- * determined.
+ * relative to the repository root. Returns undefined if no remote is found
  */
-export async function repoInfo(filePath: string): Promise<[string, string, string]> {
-    let remoteURL = ''
-    let branch = ''
-    let fileRelative = ''
+export async function repoInfo(filePath: string): Promise<RepositoryInfo | undefined> {
     try {
         // Determine repository root directory.
         const fileDirectory = path.dirname(filePath)
         const repoRoot = await gitRootDirectory(fileDirectory)
 
-        // Determine file path, relative to repository root.
-        fileRelative = filePath.slice(repoRoot.length + 1)
-        remoteURL = await gitDefaultRemoteURL(repoRoot)
-        branch = await gitBranch(repoRoot)
+        // Determine file path relative to repository root.
+        let fileRelative = filePath.slice(repoRoot.length + 1)
+
+        const remoteNameAndBranch = await gitRemoteNameAndBranch(repoRoot)
+        const { branch, remoteName } = remoteNameAndBranch
+        const remoteURL = await gitRemoteURL(repoRoot, remoteName)
+
         if (process.platform === 'win32') {
             fileRelative = fileRelative.replace(/\\/g, '/')
         }
+        log.appendLine(`repoInfo(${filePath}): remoteURL="${remoteURL}" branch="${branch}" fileRel="${fileRelative}"`)
+        return { remoteURL, branch, fileRelative }
     } catch (error) {
         log.appendLine(`repoInfo(${filePath}): ${error as string}`)
+        return undefined
     }
-    log.appendLine(`repoInfo(${filePath}): remoteURL="${remoteURL}" branch="${branch}" fileRel="${fileRelative}"`)
-    return [remoteURL, branch, fileRelative]
 }