parse module references as whole modules

Module references, like resource references, need to always return the
and object containing all instances in order to handle modules as single
values, and to postpone index evaluation to when the expression as whole
is evaluated.

addrs/parse_ref.go

@@ -120,10 +120,9 @@ func parseRef(traversal hcl.Traversal) (*Reference, tfdiags.Diagnostics) {
 			return nil, diags
 		}
 
-		// A traversal starting with "module" can either be a reference to
-		// an entire module instance or to a single output from a module
-		// instance, depending on what we find after this introducer.
-
+		// A traversal starting with "module" can either be a reference to an
+		// entire module, or to a single output from a module instance,
+		// depending on what we find after this introducer.
 		callInstance := ModuleCallInstance{
 			Call: ModuleCall{
 				Name: callName,
@@ -132,12 +131,12 @@ func parseRef(traversal hcl.Traversal) (*Reference, tfdiags.Diagnostics) {
 		}
 
 		if len(remain) == 0 {
-			// Reference to an entire module instance. Might alternatively
-			// be a reference to a collection of instances of a particular
-			// module, but the caller will need to deal with that ambiguity
-			// since we don't have enough context here.
+			// Reference to an entire module. Might alternatively be a
+			// reference to a single instance of a particular module, but the
+			// caller will need to deal with that ambiguity since we don't have
+			// enough context here.
 			return &Reference{
-				Subject:     callInstance,
+				Subject:     callInstance.Call,
 				SourceRange: tfdiags.SourceRangeFromHCL(callRange),
 				Remaining:   remain,
 			}, diags

addrs/parse_ref_test.go

@@ -281,11 +281,9 @@ func TestParseRef(t *testing.T) {
 		{
 			`module.foo`,
 			&Reference{
-				Subject: ModuleCallInstance{
-					Call: ModuleCall{
+				Subject: ModuleCall{
 					Name: "foo",
 				},
-				},
 				SourceRange: tfdiags.SourceRange{
 					Start: tfdiags.SourcePos{Line: 1, Column: 1, Byte: 0},
 					End:   tfdiags.SourcePos{Line: 1, Column: 11, Byte: 10},