test: Provide tests for client introspection query

tests/integration/schema/client_introspection/altair_graphiql_postman_2023.gql

@@ -0,0 +1,91 @@
+query IntrospectionQuery {
+  __schema {
+    queryType { name }
+    mutationType { name }
+    subscriptionType { name }
+    types {
+      ...FullType
+    }
+    directives {
+      name
+      description
+      locations
+      args {
+        ...InputValue
+      }
+    }
+  }
+}
+
+fragment FullType on __Type {
+  kind
+  name
+  description
+  fields(includeDeprecated: true) {
+    name
+    description
+    args {
+      ...InputValue
+    }
+    type {
+      ...TypeRef
+    }
+    isDeprecated
+    deprecationReason
+  }
+  inputFields {
+    ...InputValue
+  }
+  interfaces {
+    ...TypeRef
+  }
+  enumValues(includeDeprecated: true) {
+    name
+    description
+    isDeprecated
+    deprecationReason
+  }
+  possibleTypes {
+    ...TypeRef
+  }
+}
+
+fragment InputValue on __InputValue {
+  name
+  description
+  type { ...TypeRef }
+  defaultValue
+}
+
+fragment TypeRef on __Type {
+  kind
+  name
+  ofType {
+    kind
+    name
+    ofType {
+      kind
+      name
+      ofType {
+        kind
+        name
+        ofType {
+          kind
+          name
+          ofType {
+            kind
+            name
+            ofType {
+              kind
+              name
+              ofType {
+                kind
+                name
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+}

tests/integration/schema/client_introspection/one_many_test.go

@@ -0,0 +1,47 @@
+// Copyright 2023 Democratized Data Foundation
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+package client_introspection
+
+import (
+	_ "embed"
+	"testing"
+
+	testUtils "github.com/sourcenetwork/defradb/tests/integration"
+)
+
+func TestClientIntrospectionWithOneToManySchema(t *testing.T) {
+	test := testUtils.TestCase{
+		Actions: []any{
+			testUtils.SchemaUpdate{
+				Schema: `
+				type Book {
+					name: String
+					author: Author
+				}
+				type Author {
+					name: String
+					published: [Book]
+				}
+				`,
+			},
+			testUtils.ClientIntrospectionRequest{
+				Request: clientIntrospectionQuery,
+				// TODO: this should pass without error.
+				// https://github.com/sourcenetwork/defradb/issues/1502
+				ExpectedError: "Unknown kind of type: ",
+				// TODO: this should pass without error.
+				// https://github.com/sourcenetwork/defradb/issues/1463
+				// ExpectedError: "InputFields are missing",
+			},
+		},
+	}
+	testUtils.ExecuteTestCase(t, []string{"Book", "Author"}, test)
+}

tests/integration/schema/client_introspection/simple_test.go

@@ -0,0 +1,32 @@
+// Copyright 2023 Democratized Data Foundation
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+package client_introspection
+
+import (
+	_ "embed"
+	"testing"
+
+	testUtils "github.com/sourcenetwork/defradb/tests/integration"
+)
+
+//go:embed altair_graphiql_postman_2023.gql
+var clientIntrospectionQuery string
+
+func TestClientIntrospectionBasic(t *testing.T) {
+	test := testUtils.TestCase{
+		Actions: []any{
+			testUtils.ClientIntrospectionRequest{
+				Request: clientIntrospectionQuery,
+			},
+		},
+	}
+	testUtils.ExecuteTestCase(t, []string{}, test)
+}

tests/integration/test_case.go

@@ -251,3 +251,17 @@ type IntrospectionRequest struct {
 	// contains this string.
 	ExpectedError string
 }
+
+// ClientIntrospectionRequest represents a GraphQL client introspection request.
+// The GraphQL clients usually use this to fetch the schema state with a default introspection
+// query they provide.
+type ClientIntrospectionRequest struct {
+	// The introspection request to use when fetching schema state.
+	Request string
+
+	// Any error expected from the action. Optional.
+	//
+	// String can be a partial, and the test will pass if an error is returned that
+	// contains this string.
+	ExpectedError string
+}

tests/integration/utils2.go

@@ -384,6 +384,9 @@ func executeTestCase(
 		case IntrospectionRequest:
 			assertIntrospectionResults(ctx, t, testCase.Description, db, action)
 
+		case ClientIntrospectionRequest:
+			assertClientIntrospectionResults(ctx, t, testCase.Description, db, action)
+
 		case WaitForSync:
 			waitForSync(t, testCase, action, syncChans)
 
@@ -1179,6 +1182,55 @@ func assertIntrospectionResults(
 	return false
 }
 
+// Asserts that the client introspection results conform to our expectations.
+func assertClientIntrospectionResults(
+	ctx context.Context,
+	t *testing.T,
+	description string,
+	db client.DB,
+	action ClientIntrospectionRequest,
+) bool {
+	result := db.ExecRequest(ctx, action.Request)
+
+	if AssertErrors(t, description, result.GQL.Errors, action.ExpectedError) {
+		return true
+	}
+	resultantData := result.GQL.Data.(map[string]any)
+
+	if len(resultantData) == 0 {
+		return false
+	}
+
+	// Iterate through all types, validating each type definition.
+	// Inspired from buildClientSchema.ts from graphql-js,
+	// which is one way that clients do validate the schema.
+	types := resultantData["__schema"].(map[string]any)["types"].([]any)
+
+	for _, typeData := range types {
+		typeDef := typeData.(map[string]any)
+		kind := typeDef["kind"].(string)
+
+		switch kind {
+		case "SCALAR", "INTERFACE", "UNION", "ENUM":
+			// No validation for these types in this test
+		case "OBJECT":
+			fields := typeDef["fields"]
+			if fields == nil {
+				t.Errorf("Fields are missing for OBJECT type %v", typeDef["name"])
+			}
+		case "INPUT_OBJECT":
+			inputFields := typeDef["inputFields"]
+			if inputFields == nil {
+				t.Errorf("InputFields are missing for INPUT_OBJECT type %v", typeDef["name"])
+			}
+		default:
+			// t.Errorf("Unknown type kind: %v", kind)
+		}
+	}
+
+	return true
+}
+
 // Asserts that the `actual` contains the given `contains` value according to the logic
 // described on the [RequestTestCase.ContainsData] property.
 func assertContains(t *testing.T, contains map[string]any, actual map[string]any) {