Git Reset — Hard Reset on Main Lost 8 Developers 2 Hours

# io.thecodeforge — Git Reset Modes

# ─────────────────────────────────────────────────────────────
# Current state: 3 commits ahead of where we want to be
# ─────────────────────────────────────────────────────────────
git log --oneline
# d4f8b3c (HEAD) Add unit tests
# 9c3e8a2 Fix null check
# 7b2d4f1 Add backoff logic
# a3f9c2e (origin/main) Initial PaymentRetryService

# ─────────────────────────────────────────────────────────────
# --soft: undo commits, keep changes STAGED
# ─────────────────────────────────────────────────────────────
git reset --soft HEAD~3
git status
# Changes to be committed: all 3 commits' changes are staged
# Use case: squash 3 commits into 1 clean commit
git commit -m "feat(payment): add retry logic with exponential backoff and unit tests"

# ─────────────────────────────────────────────────────────────
# --mixed (default): undo commits, keep changes UNSTAGED
# ─────────────────────────────────────────────────────────────
git reset HEAD~3
# or: git reset --mixed HEAD~3
git status
# Changes not staged for commit: all 3 commits' changes in working dir
# Use case: regroup changes before re-adding selectively
git add src/main/java/io/thecodeforge/payment/PaymentRetryService.java
git commit -m "feat(payment): add retry logic with exponential backoff"

# ─────────────────────────────────────────────────────────────
# --hard: undo commits, DISCARD changes entirely
# ─────────────────────────────────────────────────────────────
git reset --hard HEAD~3
git status
# nothing to commit, working tree clean
# WARNING: the changes from those 3 commits are gone

# ─────────────────────────────────────────────────────────────
# Reset to a specific commit hash
# ─────────────────────────────────────────────────────────────
git reset --soft a3f9c2e
git reset --hard a3f9c2e

# ─────────────────────────────────────────────────────────────
# Reset a single file (unstage it from the index)
# ─────────────────────────────────────────────────────────────
git reset HEAD -- src/main/java/io/thecodeforge/payment/PaymentService.java
# This unstages the file but does NOT change the working directory content.

# io.thecodeforge — Reset vs Revert

# ─────────────────────────────────────────────────────────────
# RESET: rewrites history (local branches only)
# ─────────────────────────────────────────────────────────────
git reset --hard HEAD~1    # Undo last commit, discard changes
git reset --soft HEAD~1    # Undo last commit, keep changes staged
# If already pushed: requires force push — DON'T do on shared branches
git push origin feature/my-branch --force-with-lease

# ─────────────────────────────────────────────────────────────
# REVERT: adds a new 'undo' commit (safe for shared branches)
# ─────────────────────────────────────────────────────────────
git revert HEAD            # Undo last commit
git revert a3f9c2e        # Undo specific commit
git revert HEAD~3..HEAD   # Undo last 3 commits (creates 3 revert commits)
git revert HEAD~3..HEAD --no-commit  # Stage all reverts, commit once
git push origin main      # Normal push — history intact

# ─────────────────────────────────────────────────────────────
# DECISION: reset or revert?
# ─────────────────────────────────────────────────────────────
# Branch is local-only (not pushed)?  -> reset is safe
# Branch is shared (main, develop)?   -> revert is required
# Need to undo a specific commit?     -> revert <hash>
# Need to squash local commits?       -> reset --soft HEAD~N

# io.thecodeforge — Recover from Bad --hard Reset

# ─────────────────────────────────────────────────────────────
# SCENARIO: You ran git reset --hard and lost committed work
# ─────────────────────────────────────────────────────────────

# Step 1: Find the lost commit in reflog
git reflog
# Output:
# a3f9c2e HEAD@{0}: reset: moving to HEAD~3
# d4f8b3c HEAD@{1}: commit: Add unit tests
# 9c3e8a2 HEAD@{2}: commit: Fix null check
# 7b2d4f1 HEAD@{3}: commit: Add backoff logic

# Step 2: Recreate a branch at the lost commit
git branch recovery d4f8b3c
# Or reset forward to restore the commits:
git reset --hard d4f8b3c

# Step 3: Verify the recovery
git log --oneline -3
# d4f8b3c Add unit tests
# 9c3e8a2 Fix null check
# 7b2d4f1 Add backoff logic

# ─────────────────────────────────────────────────────────────
# SCENARIO: You ran git reset --hard and lost UNCOMMITTED work
# ─────────────────────────────────────────────────────────────

# Uncommitted changes are NOT in reflog.
# Recovery options:

# Option 1: Check if the changes were staged before reset
# Staged changes may be recoverable as orphaned blobs:
git fsck --unreachable | grep blob
# This lists blob objects that are not referenced by any commit.
# Some may be your lost file contents.

# Option 2: Check editor local history
# VS Code: right-click file > Local History
# IntelliJ: right-click file > Local History > Show History
# These may have snapshots of your uncommitted changes.

# ─────────────────────────────────────────────────────────────
# PREVENTION: Always check status before --hard
# ─────────────────────────────────────────────────────────────
git status
# If dirty: git stash first, then reset, then git stash pop