fixes regression in compiler.Compile() contract

#1679 introduced
a flag to loosen validation of the schema definition.

This PR introduced a subtle but breaking change in the contract
of the compile.Compile() method:
- before `Compile()` would fail if no object type prefix was defined
  _by default_. It supported compiling without prefix by setting the
  expected object prefix to "empty string", but this required the client
  to set that up explicitly.
- with the recent changes, `compile.Compile()` would by default allow
  schemas without prefix

The new default seems _unsafe_ compared to the original behavior.

This commit reverts that change and introduces a new Option
`AllowUnprefixedObjectType`, so that they are forced to opt in if they
want to ignore prefixes. It's more verbose but safer.

- tests to explicitly state this formerly implicit contract were added
- tests for `SkipValidation` were also added

internal/graph/computed/computecheck_test.go

@@ -937,7 +937,7 @@ func writeCaveatedTuples(ctx context.Context, _ *testing.T, ds datastore.Datasto
 	compiled, err := compiler.Compile(compiler.InputSchema{
 		Source:       "schema",
 		SchemaString: schema,
-	})
+	}, compiler.AllowUnprefixedObjectType())
 	if err != nil {
 		return datastore.NoRevision, err
 	}

internal/namespace/annotate_test.go

@@ -29,7 +29,7 @@ func TestAnnotateNamespace(t *testing.T) {
 	permission other = editor - viewer
 	permission also_aliased = viewer
 }`,
-	})
+	}, compiler.AllowUnprefixedObjectType())
 	require.NoError(err)
 
 	lastRevision, err := ds.HeadRevision(context.Background())

internal/namespace/canonicalization_test.go

@@ -518,7 +518,7 @@ func TestCanonicalizationComparison(t *testing.T) {
 			compiled, err := compiler.Compile(compiler.InputSchema{
 				Source:       input.Source("schema"),
 				SchemaString: schemaText,
-			})
+			}, compiler.AllowUnprefixedObjectType())
 			require.NoError(err)
 
 			lastRevision, err := ds.HeadRevision(context.Background())

internal/services/shared/schema_test.go

@@ -44,7 +44,7 @@ func TestApplySchemaChanges(t *testing.T) {
 			  value == 22
 			}
 		`,
-	})
+	}, compiler.AllowUnprefixedObjectType())
 	require.NoError(err)
 
 	validated, err := ValidateSchemaChanges(context.Background(), compiled, false)

internal/services/v1/permissions_test.go

@@ -347,7 +347,7 @@ func TestCheckPermissionWithDebugInfo(t *testing.T) {
 	compiled, err := compiler.Compile(compiler.InputSchema{
 		Source:       input.Source("schema"),
 		SchemaString: debugInfo.SchemaUsed,
-	})
+	}, compiler.AllowUnprefixedObjectType())
 	require.NoError(err, "Invalid schema: %s", debugInfo.SchemaUsed)
 	require.Equal(4, len(compiled.OrderedDefinitions))
 }

internal/services/v1/schema.go

@@ -106,7 +106,7 @@ func (ss *schemaServer) WriteSchema(ctx context.Context, in *v1.WriteSchemaReque
 	compiled, err := compiler.Compile(compiler.InputSchema{
 		Source:       input.Source("schema"),
 		SchemaString: in.GetSchema(),
-	})
+	}, compiler.AllowUnprefixedObjectType())
 	if err != nil {
 		return nil, ss.rewriteError(ctx, err)
 	}

internal/testfixtures/datastore.go

@@ -219,7 +219,7 @@ func DatastoreFromSchemaAndTestRelationships(ds datastore.Datastore, schema stri
 	compiled, err := compiler.Compile(compiler.InputSchema{
 		Source:       input.Source("schema"),
 		SchemaString: schema,
-	})
+	}, compiler.AllowUnprefixedObjectType())
 	require.NoError(err)
 
 	_ = writeDefinitions(validating, require, compiled.ObjectDefinitions, compiled.CaveatDefinitions)

pkg/datastore/test/namespace.go

@@ -261,7 +261,7 @@ definition document {
 	compiled, err := compiler.Compile(compiler.InputSchema{
 		Source:       input.Source("schema"),
 		SchemaString: schemaString,
-	})
+	}, compiler.AllowUnprefixedObjectType())
 	require.NoError(err)
 	require.Equal(2, len(compiled.OrderedDefinitions))
 

pkg/development/schema.go

@@ -15,7 +15,7 @@ func CompileSchema(schema string) (*compiler.CompiledSchema, *devinterface.Devel
 	compiled, err := compiler.Compile(compiler.InputSchema{
 		Source:       input.Source("schema"),
 		SchemaString: schema,
-	})
+	}, compiler.AllowUnprefixedObjectType())
 
 	var contextError compiler.ErrorWithContext
 	if errors.As(err, &contextError) {

pkg/schemadsl/compiler/compiler.go

@@ -47,15 +47,24 @@ type config struct {
 }
 
 func SkipValidation() Option { return func(cfg *config) { cfg.skipValidation = true } }
-func ObjectTypePrefix(prefix *string) Option {
-	return func(cfg *config) { cfg.objectTypePrefix = prefix }
+
+func ObjectTypePrefix(prefix string) ObjectPrefixOption {
+	return func(cfg *config) { cfg.objectTypePrefix = &prefix }
+}
+
+func AllowUnprefixedObjectType() ObjectPrefixOption {
+	return func(cfg *config) { cfg.objectTypePrefix = new(string) }
 }
 
 type Option func(*config)
 
+type ObjectPrefixOption func(*config)
+
 // Compile compilers the input schema into a set of namespace definition protos.
-func Compile(schema InputSchema, opts ...Option) (*CompiledSchema, error) {
-	cfg := &config{objectTypePrefix: new(string)}
+func Compile(schema InputSchema, prefix ObjectPrefixOption, opts ...Option) (*CompiledSchema, error) {
+	cfg := &config{}
+	prefix(cfg) // required option
+
 	for _, fn := range opts {
 		fn(cfg)
 	}