ts_yarn_init

#!/bin/bash -eu

# ****************************************************************************
# DESCRIPTON
#    Creates a yarn based typescript project
# 
#    Installation steps friendly copied from:
#
#    https://losikov.medium.com/
#    part-1-project-initial-setup-typescript-node-js-31ba3aa7fbf1
# ****************************************************************************

# bugs and hints: lrsklemstein@gmail.com


# --- constants

readonly PROG=${0##*/}


# --- functions

msg() {
    echo "[$PROG] $*" >&2
}

abort() {
    msg "$*"
    exit 1
}


# --- main

if [ $# -ne 1  ]
then
    echo "usage: $PROG DIR"
    exit 2
fi

project_dir="$(readlink -f $1)"

src_dir=$project_dir/src
out_dir=$project_dir/dist
tst_dir=$project_dir/test

app_ts=$src_dir/app.ts
app_js=$out_dir/app.js

jest_cfg=$project_dir/jest.config.js



# using an existing dir is only allowed with $PWD and without package.json
if [ -d "$project_dir" ]
then
    project_dir_norm=$(readlink -e "$project_dir")
    pwd_norm=$(readlink -e "$PWD")

    if [ "$project_dir_norm" != "$pwd_norm" ]
    then
        abort "project dir \"$project_dir\" already exist."
    fi

    if [ -f "$project_dir/package.json" ]
    then
        abort "project dir \"$project_dir\" contains a package.json"
    fi
fi

mkdir -p "$project_dir"

cd "$project_dir"


msg 'init...'
yarn init -y

msg "Install dev dependencies..."
yarn add --dev typescript jest ts-jest @types/jest @types/node nodemon ts-node

msg 'Create tsconfig.json, required for tsc and ts-node...'

/bin/cat >$project_dir/tsconfig.json <<EOF
{
  "compilerOptions": {
    "target": "es2016",
    "lib": ["es2019"],
    "module": "commonjs",
    rootDir": "${src_dir}",
    "outDir": "${out_dir}",
    "removeComments": true,
    "esModuleInterop": true,
    "strict": true,
    "noImplicitAny": true,
    "skipLibCheck": true
  },
  "include": ["src/**/*"],
}
EOF

mkdir $src_dir $out_dir $tst_dir

msg "Create initial ${app_ts}..."
/bin/cat >$app_ts << EOF
// your code here...

console.log('Hello from app.ts...');
EOF

msg "Create jest ${jest_cfg}..."
/bin/cat >$jest_cfg <<EOF
module.exports = {
  preset: 'ts-jest',
  testEnvironment: 'node',
  transform: {
    '^.+\\.ts?$': 'babel-jest'
  },
  testRegex: '(/__tests__/.*|(\\.|/)(test|spec))\\.tsx?$',
  moduleFileExtensions: ['ts', 'tsx', 'js', 'jsx', 'json', 'node'],
};
EOF

msg "Add yarn scripts to package.json..."

# '.scripts={compile:"npx tsc", run:"node src/app.js"}' 
#
jqc='.scripts={'
jqc+='compile:"npx tsc", execute:"node '$app_js'"'
jqc+='}'

tmpf=$(mktemp)

jq "$jqc" < package.json >$tmpf

mv $tmpf package.json

msg "Done!"