packwatch/src/__tests__/index.test.ts

import * as childProcess from 'child_process'
import { readFileSync } from 'fs'

import mockFS from 'mock-fs'

import runPackwatch from '..'

jest.mock('child_process')

function getPackOutput({ packageSize, unpackedSize }) {
    return `
npm notice
npm notice 📦  footprint@0.0.0
npm notice === Tarball Contents ===
npm notice 732B  package.json
npm notice 1.8kB dist/helpers.js
npm notice 1.9kB dist/index.js
npm notice === Tarball Details ===
npm notice name:          footprint
npm notice version:       0.0.0
npm notice filename:      footprint-0.0.0.tgz
npm notice package size:  ${packageSize}
npm notice unpacked size: ${unpackedSize}
npm notice shasum:        bdf33d471543cd8126338a82a27b16a9010b8dbd
npm notice integrity:     sha512-ZZvTg9GVcJw8J[...]bkE0xlqQhlt4Q==
npm notice total files:   3
npm notice
    `
}

function getManifest() {
    try {
        return JSON.parse(readFileSync('.packwatch.json', { encoding: 'utf8' }))
    } catch {
        /* No manifest */
    }
}

function setupMockFS({
    hasPackageJSON,
    hasManifest,
    manifestLimit,
    manifestSize,
}) {
    const fs = {}

    if (hasPackageJSON) fs['package.json'] = '{}'

    if (hasManifest)
        fs['.packwatch.json'] = JSON.stringify({
            unpackedSize: '0.5 B',
            limitBytes: manifestLimit,
            limit: `${manifestLimit}  B`,
            packageSize: `${manifestSize}  B`,
            packageSizeBytes: manifestSize,
        })
    mockFS(fs)
}
describe('Packwatch', () => {
    let mockLogger
    beforeEach(() => {
        mockFS({})
        mockLogger = jest.spyOn(global.console, 'log').mockImplementation()
    })

    afterEach(jest.restoreAllMocks)

    afterAll(mockFS.restore)

    it('warns the user and errors if run away from package.json', () => {
        mockFS({})
        runPackwatch()

        expect(mockLogger.mock.calls).toHaveLength(1)
        expect(mockLogger.mock.calls[0][0]).toMatchInlineSnapshot(
            '"🤔 There is no package.json file here. Are you in the root directory of your project?"',
        )
    })

    describe('without manifest', () => {
        beforeEach(() => {
            setupMockFS({ hasPackageJSON: true })
        })

        it.each(['1 B', '1.1 B', '1 kB', '1.1 kB', '1 mB', '1.1 mB'])(
            'generates the initial manifest properly (size = %s)',
            mockSize => {
                jest.spyOn(childProcess, 'spawnSync').mockReturnValue({
                    stderr: getPackOutput({
                        packageSize: mockSize,
                        unpackedSize: mockSize,
                    }),
                })
                const returnCode = runPackwatch()
                const manifest = getManifest()
                expect(returnCode).toEqual(1)
                expect(manifest).toEqual({
                    limit: mockSize,
                    packageSize: mockSize,
                    unpackedSize: mockSize,
                })
            },
        )

        it('outputs expected messaging', () => {
            jest.spyOn(childProcess, 'spawnSync').mockReturnValue({
                stderr: getPackOutput({
                    packageSize: '1 B',
                    unpackedSize: '2 B',
                }),
            })

            runPackwatch()

            expect(mockLogger.mock.calls).toHaveLength(2)
            expect(mockLogger.mock.calls[0][0]).toMatchInlineSnapshot(`
        "📝 No Manifest to compare against! Current package stats written to .packwatch.json!
        Package size (1 B) adopted as new limit."
      `)
            expect(mockLogger.mock.calls[1][0]).toMatchInlineSnapshot(
                '"❗ 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!"',
            )
        })

        it('outputs expected messaging when not updating the manifest', () => {
            jest.spyOn(childProcess, 'spawnSync').mockReturnValue({
                stderr: getPackOutput({
                    packageSize: '1 B',
                    unpackedSize: '2 B',
                }),
            })

            runPackwatch({ isUpdatingManifest: true })

            expect(mockLogger.mock.calls).toHaveLength(1)
            expect(mockLogger.mock.calls[0][0]).toMatchInlineSnapshot(`
        "📝 No Manifest to compare against! Current package stats written to .packwatch.json!
        Package size (1 B) adopted as new limit."
      `)
        })
    })

    describe('with manifest', () => {
        it('messages when the size is equal to the limit', () => {
            setupMockFS({
                hasPackageJSON: true,
                hasManifest: true,
                manifestLimit: 1,
                manifestSize: 1,
            })
            jest.spyOn(childProcess, 'spawnSync').mockReturnValue({
                stderr: getPackOutput({
                    packageSize: '1 B',
                    unpackedSize: '2 B',
                }),
            })
            runPackwatch()
            expect(mockLogger.mock.calls).toHaveLength(1)
            expect(mockLogger.mock.calls[0][0]).toMatchInlineSnapshot(
                '"📦 Nothing to report! Your package is the same size as the latest manifest reports! (Limit: 1  B)"',
            )
        })

        it('messages when the size is lower than the limit (no growth)', () => {
            setupMockFS({
                hasPackageJSON: true,
                hasManifest: true,
                manifestLimit: 5,
                manifestSize: 1,
            })
            jest.spyOn(childProcess, 'spawnSync').mockReturnValue({
                stderr: getPackOutput({
                    packageSize: '1 B',
                    unpackedSize: '2 B',
                }),
            })
            runPackwatch()
            expect(mockLogger.mock.calls).toHaveLength(1)
            expect(mockLogger.mock.calls[0][0]).toMatchInlineSnapshot(
                '"📦 Nothing to report! Your package is the same size as the latest manifest reports! (Limit: 5  B)"',
            )
        })
        it('messages when the size is lower than the limit (growth)', () => {
            setupMockFS({
                hasPackageJSON: true,
                hasManifest: true,
                manifestLimit: 5,
                manifestSize: 2,
            })
            jest.spyOn(childProcess, 'spawnSync').mockReturnValue({
                stderr: getPackOutput({
                    packageSize: '3 B',
                    unpackedSize: '2 B',
                }),
            })
            runPackwatch()
            expect(mockLogger.mock.calls).toHaveLength(1)
            expect(mockLogger.mock.calls[0][0]).toMatchInlineSnapshot(
                '"📦 👀 Your package grew! 3 B > 2  B (Limit: 5  B)"',
            )
        })
        it('messages when the size is lower than the limit (shrinkage)', () => {
            setupMockFS({
                hasPackageJSON: true,
                hasManifest: true,
                manifestLimit: 5,
                manifestSize: 2,
            })
            jest.spyOn(childProcess, 'spawnSync').mockReturnValue({
                stderr: getPackOutput({
                    packageSize: '1 B',
                    unpackedSize: '2 B',
                }),
            })
            runPackwatch()
            expect(mockLogger.mock.calls).toHaveLength(1)
            expect(mockLogger.mock.calls[0][0]).toMatchInlineSnapshot(
                '"📦 💯 Your package shrank! 1 B < 2  B (Limit: 5  B)"',
            )
        })
        it('messages when the size exceeds the limit', () => {
            setupMockFS({
                hasPackageJSON: true,
                hasManifest: true,
                manifestLimit: 0.5,
                manifestSize: 0.5,
            })
            jest.spyOn(childProcess, 'spawnSync').mockReturnValue({
                stderr: getPackOutput({
                    packageSize: '1 B',
                    unpackedSize: '2 B',
                }),
            })
            runPackwatch()
            expect(mockLogger.mock.calls).toHaveLength(1)
            expect(mockLogger.mock.calls[0][0]).toMatchInlineSnapshot(`
        "🔥🔥📦🔥🔥 Your package exceeds the limit set in .packwatch.json! 1 B > 0.5  B
        Either update the limit by using the --update-manifest flag or trim down your packed files!"
      `)
        })

        it('messages when updating the manifest', () => {
            setupMockFS({
                hasPackageJSON: true,
                hasManifest: true,
                manifestLimit: 0.5,
                manifestSize: 0.5,
            })
            jest.spyOn(childProcess, 'spawnSync').mockReturnValue({
                stderr: getPackOutput({
                    packageSize: '1 B',
                    unpackedSize: '2 B',
                }),
            })
            runPackwatch({ isUpdatingManifest: true })
            expect(mockLogger.mock.calls).toHaveLength(1)
            expect(mockLogger.mock.calls[0][0]).toMatchInlineSnapshot(
                '"📝 Updated the manifest! Package size: 1 B, Limit: 1 B"',
            )
        })
    })
})