Forward to v1.5.1

CHANGELOG.md

@@ -1,9 +1,14 @@
+# 1.5.1 (Unreleased)
+
+* `function/stdlib`: The `merge` function will no longer panic if all given maps are empty. ([#58](https://github.com/zclconf/go-cty/pull/58))
+* `function/stdlib`: The various set-manipulation functions, like `setunion`, will no longer panic if given an unknown set value. ([#59](https://github.com/zclconf/go-cty/pull/59))
+
 # 1.5.0 (March 17, 2025)
 
 * `cty`: New `Value.HasWhollyKnownType` method, for testing whether a value's type could potentially change if any unknown values it was constructed from were to become known. ([#55](https://github.com/zclconf/go-cty/pull/55))
 * `convert`: Fix incorrect panic when converting a tuple with a dynamic-typed null member into a list or set, due to overly-liberal type unification. ([#56](https://github.com/zclconf/go-cty/pull/56))
 
-# 1.4.2 (Unreleased)
+# 1.4.2
 
 * `function/stdlib`: The `jsonencode` function will now correctly accept a null as its argument, and produce the JSON representation `"null"` rather than returning an error. ([#54](https://github.com/zclconf/go-cty/pull/54))
 * `convert`: Don't panic when asked to convert a tuple of objects to a list type constraint containing a nested `cty.DynamicPseudoType`. ([#53](https://github.com/zclconf/go-cty/pull/53))

cty/function/stdlib/collection.go

@@ -762,6 +762,9 @@ var MergeFunc = function.New(&function.Spec{
 		case allNull:
 			return cty.NullVal(retType), nil
 		case retType.IsMapType():
+			if len(outputMap) == 0 {
+				return cty.MapValEmpty(retType.ElementType()), nil
+			}
 			return cty.MapVal(outputMap), nil
 		case retType.IsObjectType(), retType.Equals(cty.DynamicPseudoType):
 			return cty.ObjectVal(outputMap), nil

cty/function/stdlib/collection_test.go

@@ -506,6 +506,14 @@ func TestMerge(t *testing.T) {
 			cty.NilVal,
 			true,
 		},
+		{ // Empty maps are allowed in merge
+			[]cty.Value{
+				cty.MapValEmpty(cty.String),
+				cty.MapValEmpty(cty.String),
+			},
+			cty.MapValEmpty(cty.String),
+			false,
+		},
 	}
 
 	for _, test := range tests {

cty/function/stdlib/set.go

@@ -167,7 +167,7 @@ func setOperationReturnType(args []cty.Value) (ret cty.Type, err error) {
 
 		// Do not unify types for empty dynamic pseudo typed collections. These
 		// will always convert to any other concrete type.
-		if arg.LengthInt() == 0 && ty.Equals(cty.DynamicPseudoType) {
+		if arg.IsKnown() && arg.LengthInt() == 0 && ty.Equals(cty.DynamicPseudoType) {
 			continue
 		}
 

cty/function/stdlib/set_test.go

@@ -76,6 +76,13 @@ func TestSetUnion(t *testing.T) {
 			},
 			cty.SetValEmpty(cty.DynamicPseudoType),
 		},
+		{
+			[]cty.Value{
+				cty.SetVal([]cty.Value{cty.StringVal("5")}),
+				cty.UnknownVal(cty.Set(cty.Number)),
+			},
+			cty.UnknownVal(cty.Set(cty.String)),
+		},
 	}
 
 	for _, test := range tests {
@@ -159,6 +166,13 @@ func TestSetIntersection(t *testing.T) {
 			},
 			cty.SetValEmpty(cty.DynamicPseudoType),
 		},
+		{
+			[]cty.Value{
+				cty.SetVal([]cty.Value{cty.StringVal("5")}),
+				cty.UnknownVal(cty.Set(cty.Number)),
+			},
+			cty.UnknownVal(cty.Set(cty.String)),
+		},
 	}
 
 	for _, test := range tests {
@@ -226,6 +240,11 @@ func TestSetSubtract(t *testing.T) {
 			cty.SetValEmpty(cty.DynamicPseudoType),
 			cty.SetValEmpty(cty.DynamicPseudoType),
 		},
+		{
+			cty.SetVal([]cty.Value{cty.StringVal("5")}),
+			cty.UnknownVal(cty.Set(cty.Number)),
+			cty.UnknownVal(cty.Set(cty.String)),
+		},
 	}
 
 	for _, test := range tests {