Post-Edit Test Runner

Post-ToolBeginnerHook Type: post-tool-use

Post-Edit Test Runner triggers after every file write or edit operation. It detects which test files correspond to the modified source file using common naming conventions (*.test.ts, *.spec.ts, __tests__/*) and runs only those tests. If no matching test file exists, it skips silently. This gives you instant feedback on whether an edit broke existing functionality, catching regressions before they compound.

testingjestvitestregressionautomation

Hook Code

#!/bin/bash
# Post-Edit Test Runner Hook
# Runs related tests after file edits

# Only trigger on file write/edit tools
if [[ "$TOOL_NAME" != "Edit" ]] && [[ "$TOOL_NAME" != "Write" ]]; then
  exit 0
fi

FILE_PATH=$(echo "$TOOL_INPUT" | jq -r '.file_path // .path // empty')

if [ -z "$FILE_PATH" ]; then
  exit 0
fi

# Skip non-source files
if ! echo "$FILE_PATH" | grep -qE '\.(ts|tsx|js|jsx|py)$'; then
  exit 0
fi

# Skip test files themselves
if echo "$FILE_PATH" | grep -qE '\.(test|spec)\.(ts|tsx|js|jsx)$'; then
  exit 0
fi

BASE_NAME=$(basename "$FILE_PATH" | sed 's/\.[^.]*$//')
DIR_NAME=$(dirname "$FILE_PATH")

# Find matching test files
TEST_FILE=""
for pattern in "$DIR_NAME/$BASE_NAME.test.ts" "$DIR_NAME/$BASE_NAME.spec.ts" "$DIR_NAME/__tests__/$BASE_NAME.test.ts"; do
  if [ -f "$pattern" ]; then
    TEST_FILE="$pattern"
    break
  fi
done

if [ -z "$TEST_FILE" ]; then
  echo "No matching test file found for $FILE_PATH, skipping."
  exit 0
fi

echo "Running tests: $TEST_FILE"
npx vitest run "$TEST_FILE" --reporter=verbose 2>&1 | tail -20
exit 0

Add this hook to your Claude Code settings or .claude/settings.json to activate.

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Post-Edit Test Runner

About Post-Edit Test Runner

Claude Code hooks let you run custom shell commands automatically in response to specific events during Claude's operation. Post-Edit Test Runner is a Post-Tool hook at the Beginner level that automates tasks at key moments in your development workflow, reducing manual steps and enforcing consistency across your team.

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