Script to run tests in Jest and get the coverage for a specific file

I needed to automate the process of running tests in Jest and getting the coverage for a specific file. I created this script to help me with that.

#!/bin/bash

# Color definitions
BLUE='\033[0;34m'
GREEN='\033[0;32m'
RED='\033[0;31m'
YELLOW='\033[1;33m'
CYAN='\033[0;36m'
NC='\033[0m' # No Color
BOLD='\033[1m'

# Function to display usage
show_usage() {
    echo -e "${YELLOW}Usage:${NC} $0 [--find-by-name] <relative-file-path> [additional test options]"
    echo -e "${YELLOW}Examples:${NC}"
    echo -e "  $0 src/components/Button.tsx --watch"
    echo -e "  $0 src/components/Button.tsx --find-by-name --watch"
    exit 1
}

# Initialize variables
FIND_BY_NAME=false
RELATIVE_FILE_PATH=""

# Parse arguments
while [[ $# -gt 0 ]]; do
    case $1 in
        --find-by-name)
            FIND_BY_NAME=true
            shift
            ;;
        *)
            if [ -z "$RELATIVE_FILE_PATH" ]; then
                RELATIVE_FILE_PATH="$1"
            else
                break  # Stop parsing and keep remaining args for test options
            fi
            shift
            ;;
    esac
done

# Check if a file name is provided
if [ -z "$RELATIVE_FILE_PATH" ]; then
    show_usage
fi

# Check if the file exists
if [ ! -f "$RELATIVE_FILE_PATH" ]; then
    echo -e "${RED}Error: ${NC}File '${YELLOW}${RELATIVE_FILE_PATH}${NC}' not found. 😕"
    exit 1
fi

FILE_PATH=$(echo "$RELATIVE_FILE_PATH" | cut -d'/' -f3-)

# Get just the file name without extension for --find-by-name mode
FILE_NAME=$(basename "$RELATIVE_FILE_PATH")
FILE_NAME_NO_EXT="${FILE_NAME%.*}"

# Construct the corresponding test file path
TEST_FILE_NAME="${FILE_PATH%.*}.test"

if [ "$FIND_BY_NAME" = true ]; then
    # Search by file name
    TEST_PATH=$(find "tests" -type f \( -name "${FILE_NAME_NO_EXT}.test.tsx" -o -name "${FILE_NAME_NO_EXT}.test.ts" \))
else
    # Original search by path
    TEST_PATH=$(find "tests" -type f \( -path "*/${TEST_FILE_NAME}.tsx" -o -path "*/${TEST_FILE_NAME}.ts" \))
fi

# Check if the test file exists
if [ -z "$TEST_PATH" ]; then
    echo -e "${RED}Error: ${NC}Test file for '${YELLOW}${RELATIVE_FILE_PATH}${NC}' not found in 'tests' directory. 😕"
    echo -e "Test file name: ${YELLOW}${FILE_NAME_NO_EXT}.test.tsx${NC}"
    echo -e "${YELLOW}Hint:${NC} If you're looking for a file by name, try using the --find-by-name flag."
    exit 1
fi

# Print test information with styling
echo -e "\n${BLUE}╔════════════════════════════════════════════════════════════╗${NC}"
echo -e "${GREEN}▶ Running Coverage Test${NC}"
echo -e "${CYAN}📁 Source file:${NC} ${RELATIVE_FILE_PATH}"
echo -e "${CYAN}🧪 Test file:${NC} ${TEST_PATH}"
echo -e "${CYAN}⚙️  Options:${NC} $@"
echo -e "${BLUE}╚════════════════════════════════════════════════════════════╝${NC}\n"

yarn test "$TEST_PATH" --coverage --collectCoverageFrom="$RELATIVE_FILE_PATH" "$@"

Usage

Test cases are in the tests folder. The script will search for the test file by path by default, if you want to search by name, you can use the --find-by-name flag.

# If they share same path
./coverage.sh src/components/Button.tsx --watch

# If the test file has a different path but the same name
./coverage.sh src/components/Button.tsx --find-by-name  --watch

Usage#

Usage