package.json

@@ -33,7 +33,9 @@
         "lint:fix": "yarn lint --fix",
         "test": "jest src",
         "test:watch": "yarn test --watchAll",
-        "test:coverage": "yarn test --coverage"
+        "test:coverage": "yarn test --coverage",
+        "types": "tsc --noEmit src/**/*.ts",
+        "types:watch": "yarn types --watch"
     },
     "devDependencies": {
         "@babel/cli": "^7.8.4",

src/__tests__/index.test.ts

@@ -2,16 +2,17 @@ import { promises as fs } from 'fs'
 import { tmpdir } from 'os'
 import { join, resolve } from 'path'
 
+import logger from '../logger'
 import type { Report } from '../index.d'
-import runPackwatch from '..'
+import packwatch from '..'
 
 async function prepareWorkspace(): Promise<string> {
-    const workspacePath = await fs.mkdtemp(`${tmpdir()}/`, { recursive: true })
+    const workspacePath = await fs.mkdtemp(`${tmpdir()}/`)
     return workspacePath
 }
 
 async function cleanUpWorkspace(paths: string[]): Promise<void> {
-    return Promise.all(
+    await Promise.all(
         paths.map(async path => fs.rmdir(path, { recursive: true })),
     )
 }
@@ -37,9 +38,13 @@ async function createManifest(
 }
 describe('Packwatch', () => {
     let mockLogger
+    let mockWarn
+    let mockError
     let workspacePath
     beforeEach(() => {
-        mockLogger = jest.spyOn(global.console, 'log').mockImplementation()
+        mockLogger = jest.spyOn(console, 'log').mockImplementation()
+        mockWarn = jest.spyOn(console, 'warn').mockImplementation()
+        mockError = jest.spyOn(console, 'error').mockImplementation()
     })
 
     afterEach(async () => {
@@ -53,7 +58,9 @@ describe('Packwatch', () => {
 
     it('warns the user and errors if run away from package.json', async () => {
         workspacePath = await prepareWorkspace()
-        runPackwatch({ cwd: workspacePath })
+        await expect(async () =>
+            packwatch({ cwd: workspacePath }),
+        ).rejects.toThrow('NOT_IN_PACKAGE_ROOT')
 
         expect(mockLogger.mock.calls).toHaveLength(1)
         expect(mockLogger.mock.calls[0][0]).toEqual(
@@ -68,7 +75,9 @@ describe('Packwatch', () => {
             workspacePath = await prepareWorkspace()
             await createPackageJson(workspacePath)
 
-            runPackwatch({ cwd: workspacePath })
+            await expect(async () =>
+                packwatch({ cwd: workspacePath }),
+            ).rejects.toThrow('NO_MANIFEST_NO_UPDATE')
 
             const generatedManifest = await fs.readFile(
                 resolve(join(workspacePath, '.packwatch.json')),
@@ -84,15 +93,18 @@ describe('Packwatch', () => {
             workspacePath = await prepareWorkspace()
             await createPackageJson(workspacePath)
 
-            runPackwatch({ cwd: workspacePath })
+            await expect(async () =>
+                packwatch({ cwd: workspacePath }),
+            ).rejects.toThrow()
 
-            expect(mockLogger.mock.calls).toHaveLength(2)
-            expect(mockLogger.mock.calls[0][0]).toEqual(
+            expect(mockWarn.mock.calls).toHaveLength(1)
+            expect(mockWarn.mock.calls[0][0]).toEqual(
                 expect.stringMatching(
                     /No Manifest to compare against! Current package stats written to \.packwatch\.json!\nPackage size \(\d+ B\) adopted as new limit\./,
                 ),
             )
-            expect(mockLogger.mock.calls[1][0]).toEqual(
+            expect(mockError.mock.calls).toHaveLength(1)
+            expect(mockError.mock.calls[0][0]).toEqual(
                 expect.stringMatching(
                     'It looks like you ran PackWatch without a manifest. To prevent accidental passes in CI or hooks, packwatch will terminate with an error. If you are running packwatch for the first time in your project, this is expected!',
                 ),
@@ -104,10 +116,10 @@ describe('Packwatch', () => {
 
             await createPackageJson(workspacePath)
 
-            runPackwatch({ cwd: workspacePath, isUpdatingManifest: true })
+            await packwatch({ cwd: workspacePath, isUpdatingManifest: true })
 
-            expect(mockLogger.mock.calls).toHaveLength(1)
-            expect(mockLogger.mock.calls[0][0]).toEqual(
+            expect(mockWarn.mock.calls).toHaveLength(1)
+            expect(mockWarn.mock.calls[0][0]).toEqual(
                 expect.stringMatching(
                     /No Manifest to compare against! Current package stats written to \.packwatch\.json!\nPackage size \(\d+ B\) adopted as new limit\./,
                 ),
@@ -125,7 +137,7 @@ describe('Packwatch', () => {
                 packageSize: '160B',
                 unpackedSize: '150B',
             })
-            runPackwatch({ cwd: workspacePath })
+            await packwatch({ cwd: workspacePath })
             expect(mockLogger.mock.calls).toHaveLength(1)
             expect(mockLogger.mock.calls[0][0]).toEqual(
                 expect.stringMatching(
@@ -144,7 +156,7 @@ describe('Packwatch', () => {
                 unpackedSize: '150B',
             })
 
-            runPackwatch({ cwd: workspacePath })
+            await packwatch({ cwd: workspacePath })
             expect(mockLogger.mock.calls).toHaveLength(1)
             expect(mockLogger.mock.calls[0][0]).toEqual(
                 expect.stringMatching(
@@ -162,7 +174,7 @@ describe('Packwatch', () => {
                 unpackedSize: '140B',
             })
 
-            runPackwatch({ cwd: workspacePath })
+            await packwatch({ cwd: workspacePath })
             expect(mockLogger.mock.calls).toHaveLength(1)
             expect(mockLogger.mock.calls[0][0]).toEqual(
                 expect.stringMatching(
@@ -180,7 +192,7 @@ describe('Packwatch', () => {
                 unpackedSize: '140B',
             })
 
-            runPackwatch({ cwd: workspacePath })
+            await packwatch({ cwd: workspacePath })
             expect(mockLogger.mock.calls).toHaveLength(1)
             expect(mockLogger.mock.calls[0][0]).toEqual(
                 expect.stringMatching(
@@ -198,9 +210,11 @@ describe('Packwatch', () => {
                 unpackedSize: '140B',
             })
 
-            runPackwatch({ cwd: workspacePath })
-            expect(mockLogger.mock.calls).toHaveLength(1)
-            expect(mockLogger.mock.calls[0][0]).toEqual(
+            await expect(async () =>
+                packwatch({ cwd: workspacePath }),
+            ).rejects.toThrow('PACKAGE_EXCEEDS_LIMIT')
+            expect(mockError.mock.calls).toHaveLength(1)
+            expect(mockError.mock.calls[0][0]).toEqual(
                 expect.stringMatching(
                     /Your package exceeds the limit set in \.packwatch\.json! \d+ B > 10B\nEither update the limit by using the --update-manifest flag or trim down your packed files!/,
                 ),
@@ -217,7 +231,7 @@ describe('Packwatch', () => {
                 unpackedSize: '140B',
             })
 
-            runPackwatch({ cwd: workspacePath, isUpdatingManifest: true })
+            await packwatch({ cwd: workspacePath, isUpdatingManifest: true })
             expect(mockLogger.mock.calls).toHaveLength(1)
             expect(mockLogger.mock.calls[0][0]).toEqual(
                 expect.stringMatching(

src/__tests__/utils.test.ts

@@ -1,4 +1,4 @@
-import { convertSizeToBytes } from './utils'
+import { convertSizeToBytes } from '../utils'
 
 describe('utils', () => {
     it.each`

src/cli.ts

@@ -1,8 +1,9 @@
 #!/usr/bin/env node
 
-import runPackwatch from '.'
+import packwatch from '.'
 
 const isUpdatingManifest = process.argv.includes('--update-manifest')
 const cwd = process.cwd()
-const processExit = runPackwatch({ cwd, isUpdatingManifest })
-process.exit(processExit)
+packwatch({ cwd, isUpdatingManifest })
+    .catch(() => process.exit(1))
+    .then(() => process.exit(0))

src/index.d.ts

@@ -1,3 +1,8 @@
+export type PackwatchArguments = {
+    cwd?: string
+    isUpdatingManifest?: boolean
+}
+
 export type Report = {
     packageSize: string
     unpackedSize?: string

src/index.ts

@@ -6,25 +6,19 @@ import {
     getCurrentPackageStats,
     getPreviousPackageStats,
 } from './utils'
+import type { PackwatchArguments } from './index.d'
+import { assertInPackageRoot } from './invariants'
+import logger from './logger'
 
 const MANIFEST_FILENAME = '.packwatch.json'
 
-export default function run({
+export default async function packwatch({
     cwd,
     isUpdatingManifest,
-}: {
-    cwd?: string
-    isUpdatingManifest?: boolean
-}): number {
-    const packageJsonPath = resolve(join(cwd, 'package.json'))
+}: PackwatchArguments): Promise<void> {
     const manifestPath = resolve(join(cwd, MANIFEST_FILENAME))
 
-    if (!existsSync(packageJsonPath)) {
-        console.log(
-            '🤔 There is no package.json file here. Are you in the root directory of your project?',
-        )
-        return 1
-    }
+    assertInPackageRoot(cwd)
 
     const currentStats = getCurrentPackageStats(cwd)
 
@@ -35,18 +29,17 @@ export default function run({
 
     if (!existsSync(manifestPath)) {
         createOrUpdateManifest({ manifestPath, current: currentStats })
-        console.log(
+        logger.warn(
             `📝 No Manifest to compare against! Current package stats written to ${MANIFEST_FILENAME}!\nPackage size (${currentStats.packageSize}) adopted as new limit.`,
         )
 
         if (!isUpdatingManifest) {
-            console.log(
+            logger.error(
                 '❗ It looks like you ran PackWatch without a manifest. To prevent accidental passes in CI or hooks, packwatch will terminate with an error. If you are running packwatch for the first time in your project, this is expected!',
             )
+            throw new Error('NO_MANIFEST_NO_UPDATE')
         }
-        // If the update flag wasn't specified, exit with a non-zero code so we
-        // don't "accidentally" pass CI builds if the manifest didn't exist
-        return isUpdatingManifest ? 0 : 1
+        return
     }
 
     const previousStats = getPreviousPackageStats(cwd)
@@ -70,10 +63,10 @@ export default function run({
             updateLimit: true,
             manifestPath,
         })
-        console.log(
+        logger.log(
             `📝 Updated the manifest! Package size: ${packageSize}, Limit: ${packageSize}`,
         )
-        return 0
+        return
     }
 
     /*
@@ -82,10 +75,10 @@ export default function run({
      */
 
     if (hasExceededLimit) {
-        console.log(
+        logger.error(
             `🔥🔥📦🔥🔥 Your package exceeds the limit set in ${MANIFEST_FILENAME}! ${packageSize} > ${limit}\nEither update the limit by using the --update-manifest flag or trim down your packed files!`,
         )
-        return 1
+        throw new Error('PACKAGE_EXCEEDS_LIMIT')
     }
 
     /*
@@ -95,17 +88,17 @@ export default function run({
      */
 
     if (packageSizeBytes > previousSizeBytes) {
-        console.log(
+        logger.log(
             `📦 👀 Your package grew! ${packageSize} > ${previousSize} (Limit: ${limit})`,
         )
     } else if (packageSizeBytes < previousSizeBytes) {
-        console.log(
+        logger.log(
             `📦 💯 Your package shrank! ${packageSize} < ${previousSize} (Limit: ${limit})`,
         )
     } else {
-        console.log(
+        logger.log(
             `📦 Nothing to report! Your package is the same size as the latest manifest reports! (Limit: ${limit})`,
         )
     }
-    return 0
+    return
 }

src/invariants.ts

@@ -0,0 +1,16 @@
+import { existsSync } from 'fs'
+import { join, resolve } from 'path'
+
+import logger from './logger'
+
+export function assertInPackageRoot(cwd: string): void {
+    const packagePath = resolve(join(cwd, 'package.json'))
+    const packageJsonExists = existsSync(packagePath)
+
+    if (!packageJsonExists) {
+        logger.log(
+            '🤔 There is no package.json file here. Are you in the root directory of your project?',
+        )
+        throw new Error('NOT_IN_PACKAGE_ROOT')
+    }
+}

src/logger.ts

@@ -0,0 +1,11 @@
+export default {
+    log: (...args: unknown[]): void => {
+        console.log(...args)
+    },
+    warn: (...args: unknown[]): void => {
+        console.warn(...args)
+    },
+    error: (...args: unknown[]): void => {
+        console.error(...args)
+    },
+}

src/utils.ts

@@ -68,6 +68,7 @@ export function createOrUpdateManifest({
 }: {
     previous?: Report
     current: Report
+    manifestPath: string
     updateLimit?: boolean
 }): void {
     const { limit } = previous || {}