Improve missing implementations error by mentioning missing names (#3972

) * Improve missing implementations error by mentioning missing names * Typo * add changeset --------- Co-authored-by: David Khourshid <davidkpiano@gmail.com>
statelyai · Apr 26, 2023 · 2b9583a · 2b9583a
1 parent 534f31d
commit 2b9583a
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Showing 3 changed files with 27 additions and 7 deletions.
diff --git a/.changeset/tough-windows-applaud.md b/.changeset/tough-windows-applaud.md
@@ -0,0 +1,5 @@
+---
+'xstate': patch
+---
+
+The "Some implementations missing" type-level error will now mention what implementations are missing.
diff --git a/packages/core/src/interpreter.ts b/packages/core/src/interpreter.ts
@@ -77,6 +77,7 @@ import * as serviceScope from './serviceScope';
 import { spawnBehavior } from './behaviors';
 import {
   AreAllImplementationsAssumedToBeProvided,
+  MissingImplementationsError,
   TypegenDisabled
 } from './typegenTypes';
 
@@ -1645,7 +1646,7 @@ export function interpret<
         any,
         TResolvedTypesMeta
       >
-    : 'Some implementations missing',
+    : MissingImplementationsError<TResolvedTypesMeta>,
   options?: InterpreterOptions
 ) {
   const interpreter = new Interpreter<

diff --git a/packages/core/src/typegenTypes.ts b/packages/core/src/typegenTypes.ts
@@ -7,7 +7,8 @@ import {
   Values,
   IsAny,
   ServiceMap,
-  Cast
+  Cast,
+  Compute
 } from './types';
 
 export interface TypegenDisabled {
@@ -108,16 +109,29 @@ export type AreAllImplementationsAssumedToBeProvided<
   ? true
   : TResolvedTypesMeta extends TypegenEnabled
   ? IsNever<
-      Values<
-        {
-          [K in keyof TMissingImplementations]: TMissingImplementations[K];
-        }
-      >
+      Values<{
+        [K in keyof TMissingImplementations]: TMissingImplementations[K];
+      }>
     > extends true
     ? true
     : false
   : true;
 
+export type MissingImplementationsError<
+  TResolvedTypesMeta,
+  TMissingImplementations = Prop<
+    Prop<TResolvedTypesMeta, 'resolved'>,
+    'missingImplementations'
+  >
+> = Compute<
+  [
+    'Some implementations missing',
+    Values<{
+      [K in keyof TMissingImplementations]: TMissingImplementations[K];
+    }>
+  ]
+>;
+
 interface AllImplementationsProvided {
   missingImplementations: {
     actions: never;