fix(devtools): remove the correct module in uninstallNuxtModule (#1019)

Author: antfubot

packages/devtools/src/server-rpc/npm.ts

@@ -3,10 +3,11 @@ import type { NpmCommandOptions, NpmCommandType, NuxtDevtoolsServerContext, Pack
 import fs from 'node:fs/promises'
 import { startSubprocess } from '@nuxt/devtools-kit'
 import { parseModule } from 'magicast'
-import { addNuxtModule, getDefaultExportOptions } from 'magicast/helpers'
+import { addNuxtModule } from 'magicast/helpers'
 import { detect } from 'package-manager-detector/detect'
 import { checkForUpdateOf } from '../npm'
 import { magicastGuard } from '../utils/magicast'
+import { removeNuxtModuleFromCode } from '../utils/nuxt-config'
 
 export function setupNpmRPC({ nuxt }: NuxtDevtoolsServerContext) {
   let detectPromise: Promise<DetectResult | null> | undefined
@@ -145,20 +146,7 @@ export function setupNpmRPC({ nuxt }: NuxtDevtoolsServerContext) {
       const filepath = nuxt.options._nuxtConfigFile
       const source = await fs.readFile(filepath, 'utf-8')
       const generated = await magicastGuard(async () => {
-        const mod = parseModule(source, { sourceFileName: filepath })
-
-        // TODO: remove module from config
-        // removeNuxtModule(mod, name)
-        const config = getDefaultExportOptions(mod)
-        config.modules ||= []
-        if (config.modules.includes(name)) {
-          Object.values(config.modules).forEach((value, index) => {
-            if (value === name)
-              config.modules.splice(index - 1, 1)
-          })
-        }
-
-        return mod.generate().code
+        return removeNuxtModuleFromCode(source, name, filepath)
       })
 
       const processId = `nuxt:remove-module:${name}`

packages/devtools/src/utils/nuxt-config.ts

@@ -0,0 +1,30 @@
+import { parseModule } from 'magicast'
+import { getDefaultExportOptions } from 'magicast/helpers'
+
+/**
+ * Return `source` with `name` removed from the Nuxt config `modules` array.
+ * Handles both string entries (`'@nuxt/image'`) and tuple entries
+ * (`['@nuxt/image', {...}]`). If the module isn't present, returns the code
+ * unchanged.
+ */
+export function removeNuxtModuleFromCode(source: string, name: string, filepath?: string): string {
+  const mod = parseModule(source, filepath ? { sourceFileName: filepath } : undefined)
+  const config = getDefaultExportOptions(mod)
+  if (!Array.isArray(config.modules))
+    return mod.generate().code
+
+  // Splice matching entries out in place (reverse order so indices stay
+  // valid as we remove) rather than reassigning a filtered array — magicast
+  // regenerates a reassigned array from scratch and drops the surrounding
+  // formatting/comments of the entries that remain.
+  for (let i = config.modules.length - 1; i >= 0; i--) {
+    const entry = config.modules[i]
+    const matches = typeof entry === 'string'
+      ? entry === name
+      : Array.isArray(entry) && entry[0] === name
+    if (matches)
+      config.modules.splice(i, 1)
+  }
+
+  return mod.generate().code
+}

packages/devtools/test/remove-nuxt-module.test.ts

@@ -0,0 +1,30 @@
+import { describe, expect, it } from 'vitest'
+import { removeNuxtModuleFromCode } from '../src/utils/nuxt-config'
+
+const base = `export default defineNuxtConfig({\n  modules: ['@nuxt/image', '@nuxt/content'],\n})\n`
+
+describe('removeNuxtModuleFromCode', () => {
+  it('removes the requested module and keeps the others', () => {
+    const out = removeNuxtModuleFromCode(base, '@nuxt/image')
+    expect(out).not.toContain('@nuxt/image')
+    expect(out).toContain('@nuxt/content')
+  })
+
+  it('removes the first module without dropping the last', () => {
+    const out = removeNuxtModuleFromCode(base, '@nuxt/image')
+    expect(out).toContain('@nuxt/content') // regression guard for the splice(-1) bug
+  })
+
+  it('removes a module declared as a tuple with options', () => {
+    const src = `export default defineNuxtConfig({\n  modules: [['@nuxt/image', { quality: 80 }], '@nuxt/content'],\n})\n`
+    const out = removeNuxtModuleFromCode(src, '@nuxt/image')
+    expect(out).not.toContain('@nuxt/image')
+    expect(out).toContain('@nuxt/content')
+  })
+
+  it('is a no-op when the module is absent', () => {
+    const out = removeNuxtModuleFromCode(base, '@nuxt/not-there')
+    expect(out).toContain('@nuxt/image')
+    expect(out).toContain('@nuxt/content')
+  })
+})

plans/003-fix-uninstall-nuxt-module.md

@@ -17,7 +17,7 @@ when done.
 |------|-------|----------|--------|------------|--------|
 | 001 | Establish a Vitest unit-test baseline | P1 | S | — | DONE |
 | 002 | Add a root AGENTS.md | P2 | S | — | DONE |
-| 003 | Fix `uninstallNuxtModule` (removes wrong module → config data loss) | P1 | S | 001 | TODO |
+| 003 | Fix `uninstallNuxtModule` (removes wrong module → config data loss) | P1 | S | 001 | DONE |
 | 004 | Fix options RPC cache (inverted guard + shared-constant mutation) | P1 | S | 001 | DONE |
 | 005 | Harden assets RPC (path containment + collision-filename bug) | P1 | S–M | 001 | TODO |
 | 006 | Enforce storage denylist on item access (not just listing) | P1 | S | 001 | TODO |