Polish tests & code

src/index.test.tsx

@@ -170,21 +170,13 @@ describe('useLog', () => {
     expect(consoleLog).toBeCalledTimes(11)
     expect(consoleGroup).toBeCalledTimes(6)
   })
-
-  it('does not render anything in production', () => {
-    process.env.NODE_ENV = 'production'
-
-    const { result } = renderHook(useLog)
-    renderHook(() => result.current.log('Test'))
-    expect(consoleLog).not.toBeCalled()
-  })
-
   it('renders hook with custom styles', () => {
     renderHook(() => {
       const { log } = useLog({ styles: { componentCSS: 'color: darkBlue;' } })
       log('Test')
     })
 
+    // first call, second parameter (css for component name) should be modified
     expect(consoleGroup.mock.calls[0][1]).toBe('color: darkBlue;')
   })
 
@@ -194,7 +186,37 @@ describe('useLog', () => {
       log('Test', { styles: { componentCSS: 'color: darkRed;' } })
     })
 
-    expect(consoleGroup.mock.calls[1][1]).toBe('color: darkRed;')
+    // first call, second parameter (css for component name) should be modified
+    expect(consoleGroup.mock.calls[0][1]).toBe('color: darkRed;')
+  })
+
+  it('renders log with custom styles for subValueCSS', () => {
+    renderHook(() => {
+      const { log } = useLog({ styles: { subValueCSS: 'color: darkBlue;' } })
+      log('Test', { styles: { subValueCSS: 'color: darkRed;' } })
+    })
+
+    // first call, third parameter (css for call time) should be modified
+    expect(consoleGroup.mock.calls[0][2]).toBe('color: darkRed;')
+  })
+
+  it('renders log with custom styles for changeCSS', () => {
+    renderHook(() => {
+      const { log } = useLog({ styles: { changeCSS: 'color: darkBlue;' } })
+      log('Test', { styles: { changeCSS: 'color: darkRed;' } })
+    })
+
+    // third call, third parameter (css for new value) should be modified
+    expect(consoleLog.mock.calls[2][1]).toBe('color: darkRed;')
+  })
+
+  it('does not render anything in production', () => {
+    process.env.NODE_ENV = 'production'
+
+    const { result } = renderHook(useLog)
+    renderHook(() => result.current.log('Test'))
+
+    expect(consoleLog).not.toBeCalled()
   })
 
   it('renders anything in custom allowed environments', () => {
@@ -207,4 +229,13 @@ describe('useLog', () => {
 
     expect(consoleLog).toBeCalled()
   })
+
+  it('falls back to production for empty node_env', () => {
+    process.env.NODE_ENV = undefined
+
+    const { result } = renderHook(useLog)
+    renderHook(() => result.current.log('Test'))
+
+    expect(consoleLog).not.toBeCalled()
+  })
 })

src/index.tsx

@@ -1,40 +1,13 @@
 import { useEffect, useRef } from 'react'
+import { UseLog, UseLogReturn, Log, PrintTypes, PrintProps } from './types'
+import { getComponentName, print } from './utils'
 
 const CSS_COMPONENT = 'color: DodgerBlue'
 const CSS_CHANGE = 'color: green; font-weight: bold;'
 const CSS_SUB_VALUE = 'color: SlateGray; font-weight: thin;'
 
 const ALLOWED_NODE_ENVS = ['dev', 'development']
 
-export interface UseLog {
-  styles?: {
-    componentCSS?: string
-    changeCSS?: string
-    subValueCSS?: string
-  }
-  environments?: string[]
-}
-
-export type Log = UseLog
-
-export interface UseLogReturn {
-  log: <T>(value: T, props?: Log) => void
-}
-
-interface PrintProps<T> {
-  value: T
-  prevValue?: T
-  label: string
-  group?: string
-  type?: PrintTypes
-}
-
-export enum PrintTypes {
-  Mount = 'Mount',
-  Unmount = 'Unmount',
-  Change = 'Change',
-}
-
 export function useLog({
   styles: {
     componentCSS = CSS_COMPONENT,
@@ -43,64 +16,26 @@ export function useLog({
   } = {},
   environments = ALLOWED_NODE_ENVS,
 }: UseLog = {}): UseLogReturn {
-  const componentName =
-    (function getComponentName() {
-      try {
-        throw new Error()
-      } catch (error) {
-        if (error instanceof Error) {
-          const re = /(\w+)@|at (\w+) \(/g
-
-          re.exec(error?.stack ?? '')
-          re.exec(error?.stack ?? '')
-          const m = re.exec(error?.stack ?? '') ?? []
-
-          return String(m[1] || m[2])
-        }
-      }
-    })() ?? ''
-
-  function getGroupLabel(type: PrintTypes): string {
-    return `${String(type)} ${
-      componentName ? 'in %c<' + String(componentName) + ' /> ' : '%c'
-    }%c@ ${new Date().toLocaleTimeString()}`
-  }
+  const componentName = getComponentName()
 
   function log<T>(value: T, props?: Log): void {
-    const clonedValue = JSON.parse(JSON.stringify(value))
+    const clonedValue = JSON.parse(JSON.stringify(value)) as T
     const prevValueRef = useRef<T>()
-
-    function print<T>({
-      value,
-      label,
-      prevValue,
-      type = PrintTypes.Change,
-      group = getGroupLabel(type),
-    }: PrintProps<T>): void {
-      console.group(
-        group,
-        props?.styles?.componentCSS ?? componentCSS,
-        props?.styles?.subValueCSS ?? subValueCSS,
-      )
-
-      if (!('prevValue' in arguments[0])) {
-        console.log(`${label.padStart(14, ' ')}: ${String(value)}`)
-      } else {
-        console.log(
-          `Previous value: %c${String(arguments[0].prevValue)}`,
-          props?.styles?.subValueCSS ?? subValueCSS,
-        )
-        console.log(
-          ` Current value: %c${String(value)}`,
-          props?.styles?.changeCSS ?? changeCSS,
-        )
-      }
-
-      console.groupEnd()
+    const printProps: Pick<
+      PrintProps<T>,
+      'value' | 'styles' | 'componentName'
+    > = {
+      value: clonedValue,
+      styles: {
+        componentCSS: props?.styles?.componentCSS ?? componentCSS,
+        subValueCSS: props?.styles?.subValueCSS ?? subValueCSS,
+        changeCSS: props?.styles?.changeCSS ?? changeCSS,
+      },
+      componentName,
     }
 
-    if (environments.includes(process.env.NODE_ENV ?? '')) {
-      return (function logHooks() {
+    if (environments.includes(process.env.NODE_ENV ?? 'production')) {
+      function logHooks(): void {
         const isUnmounting = useRef(false)
         useEffect(function setIsUnmounting() {
           return function setIsUnmountingOnMount() {
@@ -111,18 +46,18 @@ export function useLog({
         useEffect(function onMount() {
           print({
             label: 'On mount',
-            value: clonedValue,
             type: PrintTypes.Mount,
+            ...printProps,
           })
 
           prevValueRef.current = value
 
           return function onUnmount() {
             print({
               label: 'On unmount',
-              value: clonedValue,
               type: PrintTypes.Unmount,
               prevValue: prevValueRef.current,
+              ...printProps,
             })
           }
         }, [])
@@ -131,16 +66,18 @@ export function useLog({
           function onChange() {
             print({
               label: 'On change',
-              value: clonedValue,
               type: PrintTypes.Change,
               prevValue: prevValueRef.current,
+              ...printProps,
             })
 
             prevValueRef.current = value
           },
           [value],
         )
-      })()
+      }
+
+      return logHooks()
     }
   }
 

src/types.ts

@@ -0,0 +1,32 @@
+export interface Styles {
+  componentCSS?: string
+  changeCSS?: string
+  subValueCSS?: string
+}
+
+export interface UseLog {
+  styles?: Styles
+  environments?: string[]
+}
+
+export type Log = UseLog
+
+export interface UseLogReturn {
+  log: <T>(value: T, props?: Log) => void
+}
+
+export interface PrintProps<T> {
+  value: T
+  prevValue?: T
+  label: string
+  group?: string
+  type?: PrintTypes
+  styles?: Styles
+  componentName: string
+}
+
+export enum PrintTypes {
+  Mount = 'Mount',
+  Unmount = 'Unmount',
+  Change = 'Change',
+}

src/utils.test.ts

@@ -0,0 +1,73 @@
+import { getGroupLabel, getComponentName, print } from './utils'
+import { PrintProps, PrintTypes } from './types'
+
+describe('utils', () => {
+  describe('getGroupLabel', () => {
+    it('renders', () => {
+      expect(getGroupLabel(PrintTypes.Change)).toEqual(
+        `Change %c%c@ ${new Date().toLocaleTimeString()}`,
+      )
+    })
+
+    it('renders with component name', () => {
+      expect(getGroupLabel(PrintTypes.Mount, 'TestComponent')).toEqual(
+        `Mount in %c<TestComponent /> %c@ ${new Date().toLocaleTimeString()}`,
+      )
+    })
+  })
+
+  describe('getComponentName', () => {
+    it('gets component name', () => {
+      expect(getComponentName()).toEqual('_callCircusTest')
+    })
+  })
+
+  describe('print', () => {
+    const consoleLog = jest.spyOn(console, 'log').mockImplementation(() => null)
+    const consoleGroup = jest
+      .spyOn(console, 'group')
+      .mockImplementation(() => null)
+    const consoleGroupEnd = jest
+      .spyOn(console, 'groupEnd')
+      .mockImplementation(() => null)
+
+    const printProps: PrintProps<string> = {
+      value: 'Test Value',
+      label: 'A Label',
+      componentName: 'SomeComponentName',
+    }
+
+    it('prints', () => {
+      print(printProps)
+
+      expect(consoleGroup).toHaveBeenCalledWith(
+        `Change in %c<SomeComponentName /> %c@ ${new Date().toLocaleTimeString()}`,
+        undefined,
+        undefined,
+      )
+      expect(consoleLog).toHaveBeenCalledWith('       A Label: Test Value')
+      expect(consoleLog).toHaveBeenCalledTimes(1)
+      expect(consoleGroupEnd).toHaveBeenCalled()
+    })
+
+    it('prints previous value', () => {
+      print({ ...printProps, prevValue: 'Some Previous value' })
+
+      expect(consoleGroup).toHaveBeenCalledWith(
+        `Change in %c<SomeComponentName /> %c@ ${new Date().toLocaleTimeString()}`,
+        undefined,
+        undefined,
+      )
+      expect(consoleLog).toHaveBeenCalledWith(
+        'Previous value: %cSome Previous value',
+        undefined,
+      )
+      expect(consoleLog).toHaveBeenCalledWith(
+        ' Current value: %cTest Value',
+        undefined,
+      )
+      expect(consoleLog).toHaveBeenCalledTimes(2)
+      expect(consoleGroupEnd).toHaveBeenCalled()
+    })
+  })
+})