fix mock type conversion in tofu test (#2144)

Signed-off-by: ollevche <ollevche@gmail.com>

CHANGELOG.md

@@ -57,6 +57,7 @@ BUG FIXES:
 * The `yamldecode` function's interpretation of scalars as numbers now conforms to the YAML 1.2 specification. In particular, the scalar value `+` is now interpreted as the string `"+"` rather than returning a parse error trying to interpret it as an integer. ([#2044](https://github.com/opentofu/opentofu/pull/2044))
 * A `module` block's `version` argument now accepts prerelease version selections using a "v" prefix before the version number. Previously this was accepted only for non-prerelease selections. ([#2124])(https://github.com/opentofu/opentofu/issues/2124)
 * The `tofu test` command doesn't try to validate mock provider definition by its underlying provider schema now. ([#2140](https://github.com/opentofu/opentofu/pull/2140))
+* Type validation for mocks and overrides are now less strict in `tofu test`. ([#2144](https://github.com/opentofu/opentofu/pull/2144))
 
 INTERNAL CHANGES:
 

internal/configs/hcl2shim/mock_value_composer.go

@@ -10,6 +10,7 @@ import (
 	"github.com/opentofu/opentofu/internal/configs/configschema"
 	"github.com/opentofu/opentofu/internal/tfdiags"
 	"github.com/zclconf/go-cty/cty"
+	"github.com/zclconf/go-cty/cty/convert"
 )
 
 // MockValueComposer provides different ways to generate mock values based on
@@ -111,19 +112,18 @@ func (mvc MockValueComposer) composeMockValueForAttributes(schema *configschema.
 		// If the attribute is computed and not configured,
 		// we use provided value from defaults.
 		if ov, ok := defaults[k]; ok {
-			typeConformanceErrs := ov.Type().TestConformance(attr.Type)
+			converted, err := convert.Convert(ov, attr.Type)
-			if len(typeConformanceErrs) == 0 {
+			if err != nil {
-				mockAttrs[k] = ov
-				continue
-			}
-
-			for _, err := range typeConformanceErrs {
 				diags = diags.Append(tfdiags.WholeContainingBody(
 					tfdiags.Warning,
 					fmt.Sprintf("Ignored mock/override field `%v`", k),
-					fmt.Sprintf("Values provided for override / mock must match resource fields types: %v.", err),
+					fmt.Sprintf("Values provided for override / mock must match resource fields types: %v.", tfdiags.FormatError(err)),
 				))
+				continue
 			}
+
+			mockAttrs[k] = converted
+			continue
 		}
 
 		// If there's no value in defaults, we generate our own.

internal/configs/hcl2shim/mock_value_composer_test.go

@@ -494,6 +494,26 @@ func TestComposeMockValueBySchema(t *testing.T) {
 			}),
 			wantWarning: true, // ignored value in defaults
 		},
+		"type-conversion": {
+			schema: &configschema.Block{
+				Attributes: map[string]*configschema.Attribute{
+					"computed-list": {
+						Type:     cty.List(cty.String),
+						Computed: true,
+					},
+				},
+			},
+			defaults: map[string]cty.Value{
+				"computed-list": cty.TupleVal([]cty.Value{
+					cty.StringVal("str"),
+				}),
+			},
+			wantVal: cty.ObjectVal(map[string]cty.Value{
+				"computed-list": cty.ListVal([]cty.Value{
+					cty.StringVal("str"),
+				}),
+			}),
+		},
 	}
 
 	for name, test := range tests {