add more type level tests for Types.MergeRight (#3828)

Effect-TS · Oct 23, 2024 · c5d537f · c5d537f
1 parent c1afd55
commit c5d537f
Showing 1 changed file with 41 additions and 9 deletions.
diff --git a/packages/effect/dtslint/Types.ts b/packages/effect/dtslint/Types.ts
@@ -57,24 +57,56 @@ hole<Types.Equals<{ a: number }, { a: number }>>()
 hole<Types.Equals<{ a: number }, { b: number }>>()
 
 // -------------------------------------------------------------------------------------
-// MergeLeft
+// MergeRecord
 // -------------------------------------------------------------------------------------
 
-// $ExpectType { a: number; b: number; }
-hole<Types.MergeLeft<{ a: number; b: number }, { a: string }>>()
+// No tests needed as MergeRecord is just an alias of MergeLeft
 
-// $ExpectType { readonly a?: number; b: number; readonly c?: string; }
-hole<Types.MergeLeft<{ readonly a?: number; b: number }, { readonly c?: string }>>()
+// -------------------------------------------------------------------------------------
+// MergeLeft
+// -------------------------------------------------------------------------------------
+
+// No tests needed as MergeLeft is just MergeRight with arguments flipped
 
 // -------------------------------------------------------------------------------------
 // MergeRight
 // -------------------------------------------------------------------------------------
 
-// $ExpectType { a: string; b: number; }
-hole<Types.MergeRight<{ a: number; b: number }, { a: string }>>()
+// mutable overwrites mutable
+// $ExpectType { a: string; c: boolean; b: number; }
+hole<Types.MergeRight<{ a: number; b: number }, { a: string; c: boolean }>>()
+
+// mutable overwrites readonly
+// $ExpectType { a: string; c: boolean; b: number; }
+hole<Types.MergeRight<{ readonly a: number; b: number }, { a: string; c: boolean }>>()
+
+// readonly overwrites mutable
+// $ExpectType { readonly a: string; c: boolean; b: number; }
+hole<Types.MergeRight<{ a: number; b: number }, { readonly a: string; c: boolean }>>()
+
+// required overwrites optional
+// $ExpectType { a: string; c: boolean; b: number; }
+hole<Types.MergeRight<{ a?: number; b: number }, { a: string; c: boolean }>>()
+
+// optional overwrites optional
+// $ExpectType { a?: string; c: boolean; b: number; }
+hole<Types.MergeRight<{ a?: number; b: number }, { a?: string; c: boolean }>>()
+
+// optional overwrites required
+// $ExpectType { a?: string; c: boolean; b: number; }
+hole<Types.MergeRight<{ a: number; b: number }, { a?: string; c: boolean }>>()
+
+// readonly optional overwrites mutable required
+// $ExpectType { readonly a?: string; c: boolean; b: number; }
+hole<Types.MergeRight<{ a: number; b: number }, { readonly a?: string; c: boolean }>>()
+
+// mutable required overwrites readonly optional
+// $ExpectType { a: string; c: boolean; b: number; }
+hole<Types.MergeRight<{ readonly a?: number; b: number }, { a: string; c: boolean }>>()
 
-// $ExpectType { readonly a?: string; b: number; }
-hole<Types.MergeRight<{ a: number; b: number }, { readonly a?: string }>>()
+// optionality of non involved keys must be preserved
+// $ExpectType { readonly c?: string; readonly a?: number; b: number; }
+hole<Types.MergeRight<{ readonly a?: number; b: number }, { readonly c?: string }>>()
 
 // -------------------------------------------------------------------------------------
 // Mutable