fix(cli): render tagged config errors

packages/opencode/src/cli/error.ts

@@ -5,13 +5,37 @@ interface ErrorLike {
   name?: string
   _tag?: string
   message?: string
-  data?: Record<string, any>
+  data?: Record<string, unknown>
+}
+
+type ConfigIssue = { message: string; path: string[] }
+
+function isRecord(input: unknown): input is Record<string, unknown> {
+  return typeof input === "object" && input !== null
 }
 
 function isTaggedError(error: unknown, tag: string): boolean {
-  return (
-    typeof error === "object" && error !== null && "_tag" in error && (error as Record<string, unknown>)._tag === tag
-  )
+  return isRecord(error) && error._tag === tag
+}
+
+function configData(input: unknown, tag: string): Record<string, unknown> | undefined {
+  if (!isRecord(input)) return undefined
+  if (input.name === tag && isRecord(input.data)) return input.data
+  if (input._tag === tag) return input
+  return undefined
+}
+
+function stringField(input: Record<string, unknown>, key: string): string | undefined {
+  return typeof input[key] === "string" ? input[key] : undefined
+}
+
+function configIssues(input: Record<string, unknown>): ConfigIssue[] {
+  return Array.isArray(input.issues)
+    ? input.issues.filter((issue): issue is ConfigIssue => {
+        if (!isRecord(issue)) return false
+        return typeof issue.message === "string" && Array.isArray(issue.path) && issue.path.every((x) => typeof x === "string")
+      })
+    : []
 }
 
 export function FormatError(input: unknown) {
@@ -35,7 +59,7 @@ export function FormatError(input: unknown) {
   // ProviderModelNotFoundError: { providerID: string, modelID: string, suggestions?: string[] }
   if (NamedError.hasName(input, "ProviderModelNotFoundError")) {
     const data = (input as ErrorLike).data
-    const suggestions: string[] = Array.isArray(data?.suggestions) ? data.suggestions : []
+    const suggestions = Array.isArray(data?.suggestions) ? data.suggestions.filter((x) => typeof x === "string") : []
     return [
       `Model not found: ${data?.providerID}/${data?.modelID}`,
       ...(suggestions.length ? ["Did you mean: " + suggestions.join(", ")] : []),
@@ -50,28 +74,30 @@ export function FormatError(input: unknown) {
   }
 
   // ConfigJsonError: { path: string, message?: string }
-  if (NamedError.hasName(input, "ConfigJsonError")) {
-    const data = (input as ErrorLike).data
-    return `Config file at ${data?.path} is not valid JSON(C)` + (data?.message ? `: ${data.message}` : "")
+  const configJson = configData(input, "ConfigJsonError")
+  if (configJson) {
+    const message = stringField(configJson, "message")
+    return `Config file at ${stringField(configJson, "path")} is not valid JSON(C)` + (message ? `: ${message}` : "")
   }
 
   // ConfigDirectoryTypoError: { dir: string, path: string, suggestion: string }
-  if (NamedError.hasName(input, "ConfigDirectoryTypoError")) {
-    const data = (input as ErrorLike).data
-    return `Directory "${data?.dir}" in ${data?.path} is not valid. Rename the directory to "${data?.suggestion}" or remove it. This is a common typo.`
+  const configDirectoryTypo = configData(input, "ConfigDirectoryTypoError")
+  if (configDirectoryTypo) {
+    return `Directory "${stringField(configDirectoryTypo, "dir")}" in ${stringField(configDirectoryTypo, "path")} is not valid. Rename the directory to "${stringField(configDirectoryTypo, "suggestion")}" or remove it. This is a common typo.`
   }
 
   // ConfigFrontmatterError: { message: string }
-  if (NamedError.hasName(input, "ConfigFrontmatterError")) {
-    return (input as ErrorLike).data?.message ?? ""
+  const configFrontmatter = configData(input, "ConfigFrontmatterError")
+  if (configFrontmatter) {
+    return stringField(configFrontmatter, "message") ?? ""
   }
 
   // ConfigInvalidError: { path?: string, message?: string, issues?: Array<{ message: string, path: string[] }> }
-  if (NamedError.hasName(input, "ConfigInvalidError")) {
-    const data = (input as ErrorLike).data
-    const path = data?.path
-    const message = data?.message
-    const issues: Array<{ message: string; path: string[] }> = Array.isArray(data?.issues) ? data.issues : []
+  const configInvalid = configData(input, "ConfigInvalidError")
+  if (configInvalid) {
+    const path = stringField(configInvalid, "path")
+    const message = stringField(configInvalid, "message")
+    const issues = configIssues(configInvalid)
     return [
       `Configuration is invalid${path && path !== "config" ? ` at ${path}` : ""}` + (message ? `: ${message}` : ""),
       ...issues.map((issue) => "↳ " + issue.message + " " + issue.path.join(".")),

packages/opencode/test/cli/error.test.ts

@@ -4,6 +4,41 @@ import { FormatError } from "../../src/cli/error"
 import { UI } from "../../src/cli/ui"
 
 describe("cli.error", () => {
+  test("formats legacy and tagged config errors the same way", () => {
+    const cases = [
+      {
+        tag: "ConfigJsonError",
+        data: { path: "/tmp/opencode.jsonc", message: "Unexpected token" },
+        expected: "Config file at /tmp/opencode.jsonc is not valid JSON(C): Unexpected token",
+      },
+      {
+        tag: "ConfigDirectoryTypoError",
+        data: { path: "/tmp/opencode.jsonc", dir: ".opencode", suggestion: "opencode" },
+        expected:
+          'Directory ".opencode" in /tmp/opencode.jsonc is not valid. Rename the directory to "opencode" or remove it. This is a common typo.',
+      },
+      {
+        tag: "ConfigFrontmatterError",
+        data: { path: "/tmp/AGENTS.md", message: "failed frontmatter" },
+        expected: "failed frontmatter",
+      },
+      {
+        tag: "ConfigInvalidError",
+        data: {
+          path: "/tmp/opencode.jsonc",
+          message: "schema mismatch",
+          issues: [{ message: "Expected string", path: ["provider", "id"] }],
+        },
+        expected: "Configuration is invalid at /tmp/opencode.jsonc: schema mismatch\n↳ Expected string provider.id",
+      },
+    ]
+
+    for (const item of cases) {
+      expect(FormatError({ name: item.tag, data: item.data })).toBe(item.expected)
+      expect(FormatError({ _tag: item.tag, ...item.data })).toBe(item.expected)
+    }
+  })
+
   test("formats account transport errors clearly", () => {
     const error = new AccountTransportError({
       method: "POST",