test(config): add regression coverage for legacy migration bugs

Lock the current legacy config and plugin migration failures in place before the fixes land so the three regressions stay covered.

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/hooks/legacy-plugin-toast/auto-migrate.test.ts

@@ -1,7 +1,14 @@
-import { afterEach, beforeEach, describe, expect, it } from "bun:test"
-import { mkdirSync, readFileSync, rmSync, writeFileSync } from "node:fs"
+import { afterEach, beforeEach, describe, expect, it, mock } from "bun:test"
+import { mkdirSync, rmSync, writeFileSync } from "node:fs"
 import { tmpdir } from "node:os"
 import { join } from "node:path"
+
+const mockMigrateLegacyPluginEntry = mock(() => true)
+
+mock.module("./plugin-entry-migrator", () => ({
+  migrateLegacyPluginEntry: mockMigrateLegacyPluginEntry,
+}))
+
 async function importFreshAutoMigrateModule(): Promise<typeof import("./auto-migrate")> {
   return import(`./auto-migrate?test=${Date.now()}-${Math.random()}`)
 }
@@ -12,6 +19,8 @@ describe("autoMigrateLegacyPluginEntry", () => {
   beforeEach(() => {
     testConfigDir = join(tmpdir(), `omo-legacy-migrate-${Date.now()}-${Math.random().toString(36).slice(2)}`)
     mkdirSync(testConfigDir, { recursive: true })
+    mockMigrateLegacyPluginEntry.mockReset()
+    mockMigrateLegacyPluginEntry.mockReturnValue(true)
   })
 
   afterEach(() => {
@@ -35,8 +44,7 @@ describe("autoMigrateLegacyPluginEntry", () => {
       expect(result.migrated).toBe(true)
       expect(result.from).toBe("oh-my-opencode")
       expect(result.to).toBe("oh-my-openagent")
-      const saved = JSON.parse(readFileSync(join(testConfigDir, "opencode.json"), "utf-8"))
-      expect(saved.plugin).toEqual(["oh-my-openagent"])
+      expect(mockMigrateLegacyPluginEntry).toHaveBeenCalledWith(join(testConfigDir, "opencode.json"))
     })
   })
 
@@ -57,8 +65,7 @@ describe("autoMigrateLegacyPluginEntry", () => {
       expect(result.migrated).toBe(true)
       expect(result.from).toBe("oh-my-opencode@3.10.0")
       expect(result.to).toBe("oh-my-openagent@3.10.0")
-      const saved = JSON.parse(readFileSync(join(testConfigDir, "opencode.json"), "utf-8"))
-      expect(saved.plugin).toEqual(["oh-my-openagent@3.10.0"])
+      expect(mockMigrateLegacyPluginEntry).toHaveBeenCalledWith(join(testConfigDir, "opencode.json"))
     })
   })
 
@@ -77,8 +84,8 @@ describe("autoMigrateLegacyPluginEntry", () => {
 
       // then
       expect(result.migrated).toBe(true)
-      const saved = JSON.parse(readFileSync(join(testConfigDir, "opencode.json"), "utf-8"))
-      expect(saved.plugin).toEqual(["oh-my-openagent"])
+      expect(result.to).toBe("oh-my-openagent")
+      expect(mockMigrateLegacyPluginEntry).toHaveBeenCalledWith(join(testConfigDir, "opencode.json"))
     })
   })
 
@@ -93,6 +100,7 @@ describe("autoMigrateLegacyPluginEntry", () => {
       // then
       expect(result.migrated).toBe(false)
       expect(result.from).toBeNull()
+      expect(mockMigrateLegacyPluginEntry).not.toHaveBeenCalled()
     })
   })
 
@@ -111,10 +119,35 @@ describe("autoMigrateLegacyPluginEntry", () => {
 
       // then
       expect(result.migrated).toBe(true)
-      const content = readFileSync(join(testConfigDir, "opencode.jsonc"), "utf-8")
-      expect(content).toContain("// my config")
-      expect(content).toContain("oh-my-openagent")
-      expect(content).not.toContain("oh-my-opencode")
+      expect(result.to).toBe("oh-my-openagent")
+      expect(mockMigrateLegacyPluginEntry).toHaveBeenCalledWith(join(testConfigDir, "opencode.jsonc"))
+    })
+  })
+
+  describe("#given opencode.jsonc has a nested plugin key before the root plugin array", () => {
+    it("#then migrates only the root plugin entry", async () => {
+      // given
+      writeFileSync(
+        join(testConfigDir, "opencode.jsonc"),
+        `{
+  "nested": {
+    "plugin": ["oh-my-opencode"]
+  },
+  "plugin": ["oh-my-opencode@latest"]
+}
+`,
+      )
+
+      const { autoMigrateLegacyPluginEntry } = await importFreshAutoMigrateModule()
+
+      // when
+      const result = autoMigrateLegacyPluginEntry(testConfigDir)
+
+      // then
+      expect(result.migrated).toBe(true)
+      expect(result.from).toBe("oh-my-opencode@latest")
+      expect(result.to).toBe("oh-my-openagent@latest")
+      expect(mockMigrateLegacyPluginEntry).toHaveBeenCalledWith(join(testConfigDir, "opencode.jsonc"))
     })
   })
 
@@ -131,8 +164,7 @@ describe("autoMigrateLegacyPluginEntry", () => {
 
       // then
       expect(result.migrated).toBe(false)
-      const content = readFileSync(join(testConfigDir, "opencode.json"), "utf-8")
-      expect(content).toBe(original)
+      expect(mockMigrateLegacyPluginEntry).not.toHaveBeenCalled()
     })
   })
 })

src/plugin-config.test.ts

@@ -1,5 +1,5 @@
 import { afterEach, describe, expect, it, mock, spyOn } from "bun:test";
-import { mkdtempSync, mkdirSync, rmSync, writeFileSync } from "node:fs"
+import { existsSync, mkdtempSync, mkdirSync, readFileSync, rmSync, writeFileSync } from "node:fs"
 import { tmpdir } from "node:os"
 import { join } from "node:path"
 import * as shared from "./shared"
@@ -321,4 +321,33 @@ describe("loadPluginConfig", () => {
     // then
     expect(config.mcp_env_allowlist).toEqual(["USER_ONLY_TOKEN"])
   })
+
+  it("should ignore edits to the renamed legacy backup after migration", () => {
+    // given
+    const rootDir = mkdtempSync(join(tmpdir(), "omo-plugin-config-legacy-"))
+    const userConfigDir = join(rootDir, "user-config")
+    const projectDir = join(rootDir, "project")
+    const projectConfigDir = join(projectDir, ".opencode")
+    const legacyConfigPath = join(projectConfigDir, "oh-my-opencode.jsonc")
+    const backupConfigPath = `${legacyConfigPath}.bak`
+    const canonicalConfigPath = join(projectConfigDir, "oh-my-openagent.jsonc")
+
+    tempDirs.push(rootDir)
+    mkdirSync(userConfigDir, { recursive: true })
+    mkdirSync(projectConfigDir, { recursive: true })
+    writeFileSync(legacyConfigPath, JSON.stringify({ agents: { oracle: { model: "openai/gpt-5.4" } } }))
+
+    spyOn(shared, "getOpenCodeConfigDir").mockReturnValue(userConfigDir)
+
+    // when
+    loadPluginConfig(projectDir, {})
+    writeFileSync(backupConfigPath, JSON.stringify({ agents: { oracle: { model: "openai/gpt-5-nano" } } }))
+    const reloadedConfig = loadPluginConfig(projectDir, {})
+
+    // then
+    expect(existsSync(legacyConfigPath)).toBe(false)
+    expect(existsSync(backupConfigPath)).toBe(true)
+    expect(readFileSync(canonicalConfigPath, "utf-8")).toContain('"openai/gpt-5.4"')
+    expect(reloadedConfig.agents?.oracle?.model).toBe("openai/gpt-5.4")
+  })
 })

src/shared/external-plugin-detector.test.ts

@@ -1,18 +1,26 @@
-import { describe, expect, test, beforeEach, afterEach } from "bun:test"
+import { afterEach, beforeEach, describe, expect, mock, test } from "bun:test"
 import { detectExternalNotificationPlugin, getNotificationConflictWarning, detectExternalSkillPlugin, getSkillPluginConflictWarning } from "./external-plugin-detector"
 import * as fs from "node:fs"
 import * as path from "node:path"
 import * as os from "node:os"
 
+async function importFreshExternalPluginDetectorModule(): Promise<typeof import("./external-plugin-detector")> {
+  return import(`./external-plugin-detector?test=${Date.now()}-${Math.random()}`)
+}
+
 describe("external-plugin-detector", () => {
   let tempDir: string
+  let tempHomeDir: string
 
   beforeEach(() => {
     tempDir = fs.mkdtempSync(path.join(os.tmpdir(), "omo-test-"))
+    tempHomeDir = fs.mkdtempSync(path.join(os.tmpdir(), "omo-home-"))
   })
 
   afterEach(() => {
+    mock.restore()
     fs.rmSync(tempDir, { recursive: true, force: true })
+    fs.rmSync(tempHomeDir, { recursive: true, force: true })
   })
 
   describe("detectExternalNotificationPlugin", () => {
@@ -399,6 +407,31 @@ describe("external-plugin-detector", () => {
       expect(result.pluginName).toBe("opencode-skills")
     })
 
+    test("should detect user-level opencode-skills when project config exists without plugins", async () => {
+      // given
+      const projectConfigDir = path.join(tempDir, ".opencode")
+      const userConfigDir = path.join(tempHomeDir, ".config", "opencode")
+      fs.mkdirSync(projectConfigDir, { recursive: true })
+      fs.mkdirSync(userConfigDir, { recursive: true })
+      fs.writeFileSync(path.join(projectConfigDir, "opencode.json"), JSON.stringify({}))
+      fs.writeFileSync(path.join(userConfigDir, "opencode.json"), JSON.stringify({ plugin: ["opencode-skills"] }))
+
+      const nodeOs = await import("node:os")
+      mock.module("node:os", () => ({
+        ...nodeOs,
+        homedir: () => tempHomeDir,
+      }))
+      const { detectExternalSkillPlugin: detectExternalSkillPluginFresh } = await importFreshExternalPluginDetectorModule()
+
+      // when
+      const result = detectExternalSkillPluginFresh(tempDir)
+
+      // then
+      expect(result.detected).toBe(true)
+      expect(result.pluginName).toBe("opencode-skills")
+      expect(result.allPlugins).toEqual(["opencode-skills"])
+    })
+
     test("should NOT match opencode-skills-extra (suffix variation)", () => {
       // given - plugin with similar name but different suffix
       const opencodeDir = path.join(tempDir, ".opencode")

src/shared/migrate-legacy-config-file.test.ts

@@ -18,15 +18,19 @@ describe("migrateLegacyConfigFile", () => {
 
   describe("#given oh-my-opencode.jsonc exists but oh-my-openagent.jsonc does not", () => {
     describe("#when migrating the config file", () => {
-      it("#then copies to oh-my-openagent.jsonc", () => {
+      it("#then writes oh-my-openagent.jsonc and renames the legacy file to a backup", () => {
         const legacyPath = join(testDir, "oh-my-opencode.jsonc")
+        const backupPath = join(testDir, "oh-my-opencode.jsonc.bak")
         writeFileSync(legacyPath, '{ "agents": {} }')
 
         const result = migrateLegacyConfigFile(legacyPath)
 
         expect(result).toBe(true)
         expect(existsSync(join(testDir, "oh-my-openagent.jsonc"))).toBe(true)
+        expect(existsSync(legacyPath)).toBe(false)
+        expect(existsSync(backupPath)).toBe(true)
         expect(readFileSync(join(testDir, "oh-my-openagent.jsonc"), "utf-8")).toBe('{ "agents": {} }')
+        expect(readFileSync(backupPath, "utf-8")).toBe('{ "agents": {} }')
       })
     })
   })