Fetch content of a file from GitHub at a given committish

fetch_file_content_at.go

package main

import (
	"context"
	"encoding/base64"
	"fmt"
	"log"
	"os"

	"github.com/google/go-github/v63/github"
)

func fileContentAt(ctx context.Context, owner, repo, filePath, committish string) ([]byte, error) {
	client := github.NewClient(nil).WithAuthToken(os.Getenv("GITHUB_ACCESS_TOKEN"))

	fileContent, _, _, err := client.Repositories.GetContents(ctx, owner, repo, filePath, &github.RepositoryContentGetOptions{Ref: committish})

	if err != nil {
		return nil, err
	}

	return base64.StdEncoding.DecodeString(*fileContent.Content)

}

func main() {
	ctx := context.Background()

	// any of these: https://github.com/google/go-github/commits/v63.0.0/example/commitpr/main.go
	content, err := fileContentAt(ctx, "google", "go-github", "example/commitpr/main.go", "aa3fcbe7aabce60227eb210c0c81a8722770590d")

	if err != nil {
		log.Fatalf("Error fetching file content: %v", err)
	}

	fmt.Printf("%s", content)
}