refactor: split git provider adapters

lib/git/http.ts

@@ -0,0 +1,47 @@
+import { isRecord } from '@/lib/guards'
+import type { GitRemoteConfig } from './types'
+
+export class GitApiError extends Error {
+  constructor(message: string, public status: number) {
+    super(message)
+  }
+}
+
+export function isHttpError(err: unknown): err is { status: number } {
+  return isRecord(err) && typeof err.status === 'number'
+}
+
+export function encodePath(path: string) {
+  return path.split('/').map(encodeURIComponent).join('/')
+}
+
+export function getRepoApiPath(remote: GitRemoteConfig) {
+  return `/repos/${encodeURIComponent(remote.owner)}/${encodeURIComponent(remote.repo)}`
+}
+
+export function decodeBase64Content(content: string) {
+  return Buffer.from(content.replace(/\s/g, ''), 'base64').toString('utf-8')
+}
+
+export async function requestGitJson(
+  remote: GitRemoteConfig,
+  path: string,
+  init: { method?: string; body?: unknown } = {},
+): Promise<unknown> {
+  const res = await fetch(`${remote.apiBaseUrl}${path}`, {
+    method: init.method ?? 'GET',
+    headers: {
+      'Accept': 'application/json',
+      'Content-Type': 'application/json',
+      'Authorization': `token ${remote.token}`,
+    },
+    body: init.body === undefined ? undefined : JSON.stringify(init.body),
+  })
+
+  if (!res.ok) {
+    const text = await res.text()
+    throw new GitApiError(text || `Git API request failed (${res.status})`, res.status)
+  }
+
+  return res.json()
+}