added init repo

1-init-repo.js

@@ -1 +1,50 @@
-console.log('1-init-repo')
+const fs = require('fs/promises')
+
+const util = require('util')
+const zlib = require('zlib')
+const crypto = require('crypto')
+
+const deflate = util.promisify(zlib.deflate)
+
+;(async () => {
+
+    // create config
+    await fs.mkdir('./.git', { recursive: true })
+    await fs.writeFile('.git/config', `[core]\nrepositoryformatversion = 0\nfilemode = true\nbare = false\nlogallrefupdates = true\nignorecase = true\nprecomposeunicode = true\n`)
+
+    // create blob
+    const blobData = '## hello'
+    const blobWithMetadata = Buffer.from(`blob ${blobData.length}\x00${blobData}`, 'utf-8')
+    const blobBuffer = await deflate(blobWithMetadata)
+    const blobSha = crypto.createHash('sha1').update(blobWithMetadata).digest('hex')
+    await fs.mkdir(`.git/objects/${blobSha.substring(0, 2)}/`, { recursive: true })
+    await fs.writeFile(`.git/objects/${blobSha.substring(0, 2)}/${blobSha.substring(2)}`, blobBuffer)
+
+    // create tree
+    const treeChunk = Buffer.from('100644 sample.md\x00', 'utf-8')
+    const treeBlob = Buffer.from(blobSha, 'hex')
+    const treeData = Buffer.concat([treeChunk, treeBlob])
+    const treeMetadata = Buffer.from(`tree ${treeData.length}\x00`, 'utf-8')
+    const treeWithMetadata = Buffer.concat([treeMetadata, treeData])
+    const treeBuffer = await deflate(treeWithMetadata)
+    const treeSha = crypto.createHash('sha1').update(treeWithMetadata).digest('hex')
+    await fs.mkdir(`.git/objects/${treeSha.substring(0, 2)}/`, { recursive: true })
+    await fs.writeFile(`.git/objects/${treeSha.substring(0, 2)}/${treeSha.substring(2)}`, treeBuffer)
+
+    // create commit
+    const timestamp = Date. now() / 1000
+    const commitData = `tree ${treeSha}\nauthor Linus Torvalds <[email protected]> ${timestamp} +0000\ncommitter Linus Torvalds <[email protected]> ${timestamp} +0000\n\nfirst\n`
+    const commitWithMetadata = Buffer.from(`commit ${commitData.length}\x00${commitData}`, 'utf-8')
+    const commitBuffer = await deflate(commitWithMetadata)
+    const commitSha = crypto.createHash('sha1').update(commitWithMetadata).digest('hex')
+    await fs.mkdir(`.git/objects/${commitSha.substring(0, 2)}/`, { recursive: true })
+    await fs.writeFile(`.git/objects/${commitSha.substring(0, 2)}/${commitSha.substring(2)}`, commitBuffer)
+
+    // create ref
+    const refString = Buffer.from(commitSha, 'utf-8')
+    await fs.mkdir('./.git/refs/heads', { recursive: true })
+    await fs.writeFile('.git/refs/heads/master', refString)
+    await fs.writeFile('.git/HEAD', 'ref: refs/heads/master\n')
+
+})()
+