feat(logger): add the ton logger

packages/logger/src/index.spec.ts

@@ -0,0 +1,176 @@
+import {
+  formatContext,
+  printWithColor,
+  print,
+  LogLevel,
+  printWith,
+  defaultColors
+} from './index'
+
+let originalStdoutWrite = process.stdout.write
+const originalEnvLogLevel = process.env.LOG_LEVEL
+
+beforeEach(() => {
+  originalStdoutWrite = process.stdout.write
+  process.stdout.write = jest.fn()
+})
+
+afterEach(() => {
+  process.stdout.write = originalStdoutWrite
+  delete process.env.LOG_LEVEL
+  if (originalEnvLogLevel) {
+    process.env.LOG_LEVEL = originalEnvLogLevel
+  }
+})
+
+describe('formatContext', () => {
+  it(`should just add break line, \
+if type of context is not object.`, () => {
+    const input = 'text'
+    const output = `${input}\n`
+    expect(formatContext(input)).toBe(output)
+  })
+
+  it(`should stringify the object and add break line, \
+if type of context is an object.`, () => {
+    const input = { sub: { text: 'text' } }
+    const output = `${JSON.stringify(input)}\n`
+    expect(formatContext(input)).toBe(output)
+  })
+
+  it(`should stringify the object with 2 spaces and add break line, \
+if type of context is an object.`, () => {
+    const input = { sub: { text: 'text' } }
+    const output = `${JSON.stringify(input, undefined, 2)}\n`
+    expect(formatContext(input, true)).toBe(output)
+  })
+})
+
+describe('printWithColor', () => {
+  it(`should write the process.stdout without color, \
+if color is not setup.`, () => {
+    const input = 'text'
+    const output = input
+    printWithColor(input)
+    expect(process.stdout.write).toBeCalledWith(output)
+  })
+
+  it(`should write the process.stdout with color, \
+if color is setup.`, () => {
+    const input = 'text'
+    const color = '90'
+    const output = `\u001B[${color}m${input}\u001B[m`
+    printWithColor(input, color)
+    expect(process.stdout.write).toBeCalledWith(output)
+  })
+})
+
+describe('print', () => {
+  it(`should write the process.stdout, \
+if level is higher or equal to default level(debug).`, () => {
+    const input = 'text'
+    const output = `${input}\n`
+    print({}, input, input)
+    expect(process.stdout.write).toHaveBeenNthCalledWith(1, output)
+    expect(process.stdout.write).toHaveBeenNthCalledWith(2, output)
+  })
+
+  it(`should not write the process.stdout, \
+if level is smaller than process.env.LOG_LEVEL = error.`, () => {
+    const input = 'text'
+    process.env.LOG_LEVEL = 'error'
+    print({ level: LogLevel.warn }, input)
+    expect(process.stdout.write).toHaveBeenCalledTimes(0)
+  })
+
+  it(`should write the stack to process.stdout, \
+if context is error.`, () => {
+    const input = new Error('Hi There!')
+    const outputStack = `${input.stack}\n`
+    process.env.LOG_LEVEL = 'error'
+    print({ level: LogLevel.error }, input)
+    expect(process.stdout.write).toHaveBeenNthCalledWith(1, outputStack)
+  })
+
+  it(`should write the message to process.stdout, \
+if context is error and stack is missing.`, () => {
+    const input = new Error('Hi There!')
+    const outputMessage = `${input.message}\n`
+    input.stack = ''
+    process.env.LOG_LEVEL = 'error'
+    print({ level: LogLevel.error }, input)
+    expect(process.stdout.write).toHaveBeenNthCalledWith(1, outputMessage)
+  })
+})
+
+describe('printWith', () => {
+  it('should create custom logger', () => {
+    const input = 'text'
+    const color = '96'
+    const output = `\u001B[${color}m${input}\n\u001B[m`
+    const customLogger = printWith({ level: LogLevel.warn, color })
+    customLogger(input, input)
+    expect(process.stdout.write).toHaveBeenNthCalledWith(1, output)
+    expect(process.stdout.write).toHaveBeenNthCalledWith(2, output)
+  })
+
+  it('should print break line, if argument is empty', () => {
+    const color = '96'
+    const output = `\u001B[${color}m\n\u001B[m`
+    const customLogger = printWith({ level: LogLevel.warn, color })
+    customLogger()
+    expect(process.stdout.write).toHaveBeenNthCalledWith(1, output)
+  })
+})
+
+describe('logger', () => {
+  it('error', () => {
+    const input = 'text'
+    const color = defaultColors.error
+    const output = `\u001B[${color}m${input}\n\u001B[m`
+    const customLogger = printWith({ level: LogLevel.warn, color })
+    customLogger(input, input)
+    expect(process.stdout.write).toHaveBeenNthCalledWith(1, output)
+    expect(process.stdout.write).toHaveBeenNthCalledWith(2, output)
+  })
+
+  it('warn', () => {
+    const input = 'text'
+    const color = defaultColors.warn
+    const output = `\u001B[${color}m${input}\n\u001B[m`
+    const customLogger = printWith({ level: LogLevel.warn, color })
+    customLogger(input, input)
+    expect(process.stdout.write).toHaveBeenNthCalledWith(1, output)
+    expect(process.stdout.write).toHaveBeenNthCalledWith(2, output)
+  })
+
+  it('info', () => {
+    const input = 'text'
+    const color = defaultColors.info
+    const output = `\u001B[${color}m${input}\n\u001B[m`
+    const customLogger = printWith({ level: LogLevel.warn, color })
+    customLogger(input, input)
+    expect(process.stdout.write).toHaveBeenNthCalledWith(1, output)
+    expect(process.stdout.write).toHaveBeenNthCalledWith(2, output)
+  })
+
+  it('debug', () => {
+    const input = 'text'
+    const color = defaultColors.debug
+    const output = `\u001B[${color}m${input}\n\u001B[m`
+    const customLogger = printWith({ level: LogLevel.warn, color })
+    customLogger(input, input)
+    expect(process.stdout.write).toHaveBeenNthCalledWith(1, output)
+    expect(process.stdout.write).toHaveBeenNthCalledWith(2, output)
+  })
+
+  it('verbose', () => {
+    const input = 'text'
+    const color = defaultColors.verbose
+    const output = `\u001B[${color}m${input}\n\u001B[m`
+    const customLogger = printWith({ level: LogLevel.warn, color })
+    customLogger(input, input)
+    expect(process.stdout.write).toHaveBeenNthCalledWith(1, output)
+    expect(process.stdout.write).toHaveBeenNthCalledWith(2, output)
+  })
+})

packages/logger/src/index.ts

@@ -0,0 +1,135 @@
+function isObject(target: any): target is object {
+  return target !== null && typeof target === 'object'
+}
+
+function isError(target: any): target is Error {
+  return target instanceof Error
+}
+
+export enum LogLevel {
+  error = 0,
+  warn = 1,
+  info = 2,
+  debug = 3,
+  verbose = 4
+}
+
+export type LogColor = {
+  error: string
+  warn: string
+  info: string
+  debug: string
+  verbose: string
+}
+
+/**
+ * ref: https://en.wikipedia.org/wiki/ANSI_escape_code#3/4_bit
+ */
+export const defaultColors: LogColor = {
+  error: '91',
+  warn: '93',
+  info: '92',
+  debug: '97',
+  verbose: '90'
+}
+
+/**
+ * format the context
+ * @param context something you want to format
+ * @param format should beautify the object?
+ */
+export function formatContext(context: any, format?: boolean) {
+  if (!isObject(context)) {
+    return `${context}\n`
+  }
+
+  if (!format) {
+    return `${JSON.stringify(context)}\n`
+  }
+
+  return `${JSON.stringify(context, undefined, 2)}\n`
+}
+
+/**
+ * print the context with color
+ * @param context something you want to print
+ * @param color ansi code
+ * @see https://en.wikipedia.org/wiki/ANSI_escape_code#3/4_bit
+ */
+export function printWithColor(context: any, color?: string) {
+  if (!color) {
+    process.stdout.write(context)
+    return
+  }
+
+  process.stdout.write(`\u001B[${color}m${context}\u001B[m`)
+}
+
+export type LogOptions = {
+  level?: LogLevel
+  color?: string
+  format?: boolean
+}
+
+/**
+ * print it, suggest use the `printWith` to create customer logger
+ * @param param0 the options of logger
+ * @param args something you want to print
+ */
+export function print(
+  { level = LogLevel.debug, color, format }: LogOptions,
+  ...args: any[]
+) {
+  if (level <= LogLevel[process.env.LOG_LEVEL || 'debug']) {
+    args.forEach(context => {
+      if (isError(context)) {
+        printWithColor(
+          formatContext(context.stack || context.message, format),
+          color
+        )
+        return
+      }
+      printWithColor(formatContext(context, format), color)
+    })
+  }
+}
+
+/**
+ * create the custom logger function
+ * @param options the options of your custom logger
+ * @example
+ * const error = printWith({
+ *   level: LogLevel.error,
+ *   color: defaultColors.error
+ * })
+ * error('Hello World!')
+ *
+ */
+export function printWith(options: LogOptions) {
+  return (message: any = '', ...args: any[]) => print(options, message, ...args)
+}
+
+export const error = printWith({
+  level: LogLevel.error,
+  color: defaultColors.error
+})
+
+export const warn = printWith({
+  level: LogLevel.warn,
+  color: defaultColors.warn
+})
+
+export const info = printWith({
+  level: LogLevel.info,
+  color: defaultColors.info
+})
+
+export const debug = printWith({
+  level: LogLevel.debug,
+  color: defaultColors.debug
+})
+
+export const verbose = printWith({
+  level: LogLevel.verbose,
+  color: defaultColors.verbose
+})