From 4964f9b52c8a3c5a10f266c3b9740b02d6427ada Mon Sep 17 00:00:00 2001
From: Anthony Fu <anthonyfu117@hotmail.com>
Date: Fri, 25 Feb 2022 13:35:42 +0800
Subject: [PATCH] feat: dynamic imports

---
 src/context.ts        | 44 ++++++++++++++++++++++++++++++++-----------
 src/unplugin.ts       |  2 +-
 test/fixtures.test.ts |  6 +++---
 test/index.test.ts    |  8 ++++----
 4 files changed, 41 insertions(+), 19 deletions(-)

diff --git a/src/context.ts b/src/context.ts
index dd5866c1..54bf9e8e 100644
--- a/src/context.ts
+++ b/src/context.ts
@@ -5,7 +5,9 @@ import { excludeRE, stripCommentsAndStrings, separatorRE, importAsRE, toTypeDecl
 import { resolveBuiltinPresets } from './preset'
 
 interface Context {
-  imports: Import[]
+  readonly imports: Import[]
+  staticImports: Import[]
+  dynamicImports: Import[]
   matchRE: RegExp
   map: Map<string, Import>
 }
@@ -14,13 +16,17 @@ export type Unimport = ReturnType<typeof createUnimport>
 
 export function createUnimport (opts: Partial<UnimportOptions>) {
   const ctx: Context = {
-    imports: [].concat(opts.imports).filter(Boolean),
+    staticImports: [].concat(opts.imports).filter(Boolean),
+    dynamicImports: [],
+    get imports () {
+      return [...this.staticImports, ...this.dynamicImports]
+    },
     map: new Map(),
     matchRE: /__never__/g
   }
 
   // Resolve presets
-  ctx.imports.push(...resolveBuiltinPresets(opts.presets || []))
+  ctx.staticImports.push(...resolveBuiltinPresets(opts.presets || []))
 
   // Normalize imports
   for (const _import of ctx.imports) {
@@ -28,19 +34,35 @@ export function createUnimport (opts: Partial<UnimportOptions>) {
   }
 
   // Detect duplicates
-  ctx.imports = dedupeImports(ctx.imports, console.warn)
+  ctx.staticImports = dedupeImports(ctx.staticImports, console.warn)
 
-  // Create regex
-  ctx.matchRE = new RegExp(`(?:\\b|^)(${ctx.imports.map(i => escapeRE(i.as)).join('|')})(?:\\b|\\()`, 'g')
+  function reload () {
+    const imports = dedupeImports(ctx.imports, console.warn)
+    // Create regex
+    ctx.matchRE = new RegExp(`(?:\\b|^)(${imports.map(i => escapeRE(i.as)).join('|')})(?:\\b|\\()`, 'g')
 
-  // Create map
-  for (const _import of ctx.imports) {
-    ctx.map.set(_import.as, _import)
+    // Create map
+    for (const _import of imports) {
+      ctx.map.set(_import.as, _import)
+    }
+  }
+
+  function appendDynamicImports (imports: Import[]) {
+    ctx.dynamicImports.push(...imports)
   }
 
+  function clearDynamicImports () {
+    ctx.dynamicImports = []
+  }
+
+  reload()
+
   return {
+    reload,
+    appendDynamicImports,
+    clearDynamicImports,
     detectImports: (code: string) => detectImports(code, ctx),
-    addImports: (code: string, mergeExisting?: boolean) => addImports(code, ctx, mergeExisting),
+    injectImports: (code: string, mergeExisting?: boolean) => injectImports(code, ctx, mergeExisting),
     generateTypeDecarations: () => toTypeDeclrationFile(ctx.imports)
   }
 }
@@ -77,7 +99,7 @@ function detectImports (code: string, ctx: Context) {
   }
 }
 
-function addImports (code: string, ctx: Context, mergeExisting?: boolean) {
+function injectImports (code: string, ctx: Context, mergeExisting?: boolean) {
   const { isCJSContext, matchedImports } = detectImports(code, ctx)
 
   return addImportToCode(code, matchedImports, isCJSContext, mergeExisting)
diff --git a/src/unplugin.ts b/src/unplugin.ts
index a57309a3..02962bda 100644
--- a/src/unplugin.ts
+++ b/src/unplugin.ts
@@ -27,7 +27,7 @@ export default createUnplugin<Partial<UnimportPluginOptions>>((options) => {
       return filter(id)
     },
     transform (_code) {
-      const { code, s } = ctx.addImports(_code)
+      const { code, s } = ctx.injectImports(_code)
       if (code === _code) {
         return
       }
diff --git a/test/fixtures.test.ts b/test/fixtures.test.ts
index 59af4bb1..0f1200c8 100644
--- a/test/fixtures.test.ts
+++ b/test/fixtures.test.ts
@@ -7,7 +7,7 @@ import { createUnimport } from '../src/context'
 const UNMODIFIED_MARK = '@test-unmodified'
 
 describe('fixtures', async () => {
-  const { addImports } = createUnimport({
+  const { injectImports } = createUnimport({
     imports: [
       { name: 'default', from: 'default', as: 'customDefault' },
       { name: 'foobar', from: 'foobar', as: 'foobar' }
@@ -41,13 +41,13 @@ describe('fixtures', async () => {
   for (const file of files) {
     it(file, async () => {
       const code = await fs.readFile(resolve(root, file), 'utf-8')
-      const pass1 = (await addImports(code))?.code ?? code
+      const pass1 = (await injectImports(code))?.code ?? code
       if (code.includes(UNMODIFIED_MARK)) {
         expect(pass1).toBe(code)
       } else {
         expect(pass1).toMatchSnapshot()
         expect(pass1).not.toBe(code)
-        const pass2 = (await addImports(pass1))?.code ?? pass1
+        const pass2 = (await injectImports(pass1))?.code ?? pass1
         expect(pass2).toBe(pass1)
       }
     })
diff --git a/test/index.test.ts b/test/index.test.ts
index f08ff970..1935101a 100644
--- a/test/index.test.ts
+++ b/test/index.test.ts
@@ -1,12 +1,12 @@
 import { expect, describe, test } from 'vitest'
 import { createUnimport } from '../src'
 
-describe('unimport', () => {
-  test('Adds basic import', () => {
-    const { addImports } = createUnimport({
+describe('inject import', () => {
+  test('basic', () => {
+    const { injectImports } = createUnimport({
       imports: [{ name: 'fooBar', from: 'test-id' }]
     })
-    expect(addImports('console.log(fooBar())').code)
+    expect(injectImports('console.log(fooBar())').code)
       .toMatchInlineSnapshot('"import { fooBar } from \'test-id\';console.log(fooBar())"')
   })
 })