config generation: stop editing the original schema when filtering

internal/configs/configschema/copy.go

@@ -0,0 +1,71 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: BUSL-1.1
+
+package configschema
+
+// DeepCopy returns a deep copy of the schema.
+func (b *Block) DeepCopy() *Block {
+	block := &Block{
+		Description:     b.Description,
+		DescriptionKind: b.DescriptionKind,
+		Deprecated:      b.Deprecated,
+	}
+
+	if b.Attributes != nil {
+		block.Attributes = make(map[string]*Attribute, len(b.Attributes))
+	}
+	for name, a := range b.Attributes {
+		block.Attributes[name] = a.DeepCopy()
+	}
+
+	if b.BlockTypes != nil {
+		block.BlockTypes = make(map[string]*NestedBlock, len(b.BlockTypes))
+	}
+	for name, bt := range b.BlockTypes {
+		inner := bt.Block.DeepCopy()
+		block.BlockTypes[name] = &NestedBlock{
+			Block:    *inner,
+			Nesting:  bt.Nesting,
+			MinItems: bt.MinItems,
+			MaxItems: bt.MaxItems,
+		}
+	}
+
+	return block
+}
+
+// DeepCopy returns a deep copy of the schema.
+func (a *Attribute) DeepCopy() *Attribute {
+	attr := &Attribute{
+		Type:            a.Type,
+		Description:     a.Description,
+		DescriptionKind: a.DescriptionKind,
+		Deprecated:      a.Deprecated,
+		Required:        a.Required,
+		Computed:        a.Computed,
+		Optional:        a.Optional,
+		Sensitive:       a.Sensitive,
+
+		// NestedType is not copied here because it will be copied
+		// separately if it is set.
+		NestedType: nil,
+	}
+	if a.NestedType != nil {
+		attr.NestedType = a.NestedType.DeepCopy()
+	}
+	return attr
+}
+
+// DeepCopy returns a deep copy of the schema.
+func (o *Object) DeepCopy() *Object {
+	object := &Object{
+		Nesting: o.Nesting,
+	}
+	if o.Attributes != nil {
+		object.Attributes = make(map[string]*Attribute, len(o.Attributes))
+		for name, a := range o.Attributes {
+			object.Attributes[name] = a.DeepCopy()
+		}
+	}
+	return object
+}

internal/configs/configschema/filter.go

@@ -56,10 +56,11 @@ func (b *Block) filter(path cty.Path, filterAttribute FilterT[*Attribute], filte
 	for name, attrS := range b.Attributes {
 		path := path.GetAttr(name)
 		if filterAttribute == nil || !filterAttribute(path, attrS) {
-			ret.Attributes[name] = attrS
+			attr := *attrS
 			if attrS.NestedType != nil {
-				ret.Attributes[name].NestedType = filterNestedType(attrS.NestedType, path, filterAttribute)
+				attr.NestedType = filterNestedType(attrS.NestedType, path, filterAttribute)
 			}
+			ret.Attributes[name] = &attr
 		}
 	}
 
@@ -95,10 +96,11 @@ func filterNestedType(obj *Object, path cty.Path, filterAttribute FilterT[*Attri
 	for name, attrS := range obj.Attributes {
 		path := path.GetAttr(name)
 		if filterAttribute == nil || !filterAttribute(path, attrS) {
-			ret.Attributes[name] = attrS
+			attr := *attrS
 			if attrS.NestedType != nil {
-				ret.Attributes[name].NestedType = filterNestedType(attrS.NestedType, path, filterAttribute)
+				attr.NestedType = filterNestedType(attrS.NestedType, path, filterAttribute)
 			}
+			ret.Attributes[name] = &attr
 		}
 	}
 

internal/configs/configschema/filter_test.go

@@ -278,9 +278,16 @@ func TestFilter(t *testing.T) {
 
 	for name, tc := range testCases {
 		t.Run(name, func(t *testing.T) {
+			original := tc.schema.DeepCopy()
+
 			got := tc.schema.Filter(tc.filterAttribute, tc.filterBlock)
 			if !cmp.Equal(got, tc.want, cmp.Comparer(cty.Type.Equals), cmpopts.EquateEmpty()) {
-				t.Fatal(cmp.Diff(got, tc.want, cmp.Comparer(cty.Type.Equals), cmpopts.EquateEmpty()))
+				t.Error(cmp.Diff(got, tc.want, cmp.Comparer(cty.Type.Equals), cmpopts.EquateEmpty()))
+			}
+
+			// We shouldn't have edited the original schema.
+			if !cmp.Equal(tc.schema, original, cmp.Comparer(cty.Type.Equals), cmpopts.EquateEmpty()) {
+				t.Errorf("the original schema was edited when it shouldn't have been: %s", cmp.Diff(tc.schema, original, cmp.Comparer(cty.Type.Equals), cmpopts.EquateEmpty()))
 			}
 		})
 	}