test: add tests for new feature

Author: TomerAberbach

src/dependencies.test.ts

@@ -0,0 +1,66 @@
+import test from 'ava'
+import { join } from 'path'
+import { findPackagePaths, findDependencies } from './dependencies'
+
+const path = (...paths: string[]): string => join(__dirname, ...paths)
+
+test.serial('finds package paths in git monorepo', async t => {
+    const cwd = path('fixtures/monorepo/packages/package')
+    process.chdir(cwd)
+
+    const packagePaths = [
+        path('fixtures/monorepo/packages/package/package.json'),
+        path('fixtures/monorepo/package.json')
+    ]
+
+    // Should have two assertions
+    t.plan(2)
+
+    for await (const packagePath of findPackagePaths()) {
+        t.is(packagePath, packagePaths.shift())
+    }
+})
+
+test.serial('finds package paths in non-git monorepo', async t => {
+    const cwd = path('fixtures/monorepo-no-git/packages/package')
+    process.chdir(cwd)
+
+    const packagePaths = [
+        path('fixtures/monorepo-no-git/packages/package/package.json'),
+        path('fixtures/monorepo-no-git/package.json'),
+        path('../package.json')
+    ]
+
+    // Should have three assertions
+    t.plan(3)
+
+    for await (const packagePath of findPackagePaths()) {
+        t.is(packagePath, packagePaths.shift())
+    }
+})
+
+test.serial('finds dependencies in monorepo', async t => {
+    const cwd = path('fixtures/monorepo/packages/package')
+    process.chdir(cwd)
+
+    const dependencies = await findDependencies({
+        packagePaths: findPackagePaths(),
+        keys: ['dependencies'],
+        warnings: []
+    })
+
+    t.deepEqual(new Set(dependencies), new Set(['lodash', 'express', 'chalk']))
+})
+
+test.serial('finds dev dependencies in monorepo', async t => {
+    const cwd = path('fixtures/monorepo/packages/package')
+    process.chdir(cwd)
+
+    const devDependencies = await findDependencies({
+        packagePaths: findPackagePaths(),
+        keys: ['devDependencies'],
+        warnings: []
+    })
+
+    t.deepEqual(new Set(devDependencies), new Set(['typescript', 'rollup']))
+})

src/fixtures/monorepo-no-git/package.json

@@ -0,0 +1,3 @@
+{
+
+}

src/fixtures/monorepo-no-git/packages/package/package.json

@@ -0,0 +1,3 @@
+{
+
+}

src/fixtures/monorepo/package.json

@@ -0,0 +1,10 @@
+{
+  "dependencies": {
+    "lodash": "^4.17.15",
+    "chalk": "^4.0.0"
+  },
+  "devDependencies": {
+    "typescript": "^3.9.2",
+    "rollup": "^2.10.2"
+  }
+}

src/fixtures/monorepo/packages/package/package.json

@@ -0,0 +1,9 @@
+{
+  "dependencies": {
+    "lodash": "^4.17.15",
+    "express": "4.17.1"
+  },
+  "peerDependencies": {
+    "@babel/core": "^7.0.0"
+  }
+}

src/index.test.ts

@@ -1,8 +1,9 @@
 import test from 'ava'
 import { testProp, fc } from 'ava-fast-check'
 import { Arbitrary } from 'fast-check'
-import { PluginContext, Plugin } from 'rollup'
+import { PluginContext, Plugin, InputOptions } from 'rollup'
 import externals, { ExternalsOptions } from './index'
+import { join } from "path"
 
 // Returns an arbitrary for generating externals options objects
 const externalsOptionsArbitrary = (): Arbitrary<ExternalsOptions> =>
@@ -31,10 +32,30 @@ testProp(
     }
 )
 
-test('does not mark "dependencies" dependency as external by default', t => {
+test('does not mark "dependencies" dependency as external by default', async t => {
     const source = 'example'
     const importer = 'me'
-    const plugin = externals({ packagePath: './fixtures/test.json' }) as Plugin & PluginContext
+    const plugin = externals({ packagePath: './fixtures/test.json' }) as Required<Plugin> & PluginContext
 
+    await plugin.buildStart({} as InputOptions)
     t.is(plugin.resolveId(source, importer), null)
 })
+
+const path = (...paths: string[]): string => join(__dirname, ...paths)
+
+test.serial('monorepo usage', async t => {
+    const cwd = path('fixtures/monorepo/packages/package')
+    process.chdir(cwd)
+
+    const importer = 'me'
+    const plugin = externals() as Required<Plugin> & PluginContext
+    await plugin.buildStart({} as InputOptions)
+
+    for (const source of ['@babel/core', 'typescript', 'rollup']) {
+        t.false(plugin.resolveId(source, importer))
+    }
+
+    for (const source of ['lodash', 'express', 'chalk']) {
+        t.is(plugin.resolveId(source, importer), null)
+    }
+})