pre-commit hook: Ensure autoformatted files are added to the current …

…commit

The current pre-commit hook does not stage the formatted files for
committing. As a result, files like blueprint-schema.json flicker
back and forth between their formatted and unformatted state as
different contributors have different committing strategies.

This commit is an attempt to standardize that behavior. Every formatted
file that was already staged for a commit, will now be added to that
very commit. This, in theory, should prevent misformatted files from
ever being committed.

.husky/post-commit

@@ -0,0 +1,6 @@
+#!/bin/bash
+
+# Without this, git is reporting that the files formatted in the
+# pre-commit hook are still modified after committing
+UPDATED_FILES=$(git diff-tree --no-commit-id --name-only -r HEAD)
+git update-index $UPDATED_FILES

.husky/pre-commit

@@ -2,4 +2,17 @@
 # This, weirdly, breaks nx:
 # . "$(dirname -- "$0")/_/husky.sh"
 
+# Save the list of files that are staged for commit
+STAGED_FILES=$(git diff --cached --name-only --diff-filter=ACM)
+
+# Run the format command
 npm run format:uncommitted
+
+# Re-add the files that were both staged and modified
+for file in $STAGED_FILES; do
+    if git diff --name-only --diff-filter=ACM | grep -q "^$file$"; then
+        git add "$file"
+    fi
+done
+
+exit 0