Move num(NativeModule flow interface) > 1 error into `buildModuleSchema`

Summary:
**Motivation:** After this change, we can show this ParserError using the React Native Module ESLint rule. Previously when we declared more than one NativeModule spec in a file, we incorrectly reported that there were *no* NativeModule specs in the file.

Changelog: [Internal]

Reviewed By: hramos

Differential Revision: D25163299

fbshipit-source-id: 92bc09d09cdbc323e0ac1f317c40a767880f5bc2

packages/react-native-codegen/src/parsers/flow/index.js

@@ -77,14 +77,6 @@ function isModule(
     return false;
   }
 
-  if (moduleInterfaces.length > 1) {
-    throw new Error(
-      'File contains declarations of more than one module: ' +
-        moduleInterfaces.join(', ') +
-        '. Please declare exactly one module in this file.',
-    );
-  }
-
   return true;
 }
 

packages/react-native-codegen/src/parsers/flow/modules/__tests__/__snapshots__/module-parser-snapshot-test.js.snap

@@ -12,7 +12,7 @@ exports[`RN Codegen Flow Parser Fails with error message NATIVE_MODULES_WITH_REA
 
 exports[`RN Codegen Flow Parser Fails with error message NATIVE_MODULES_WITH_UNNAMED_PARAMS 1`] = `"Module NativeSampleTurboModule: All function parameters must be named."`;
 
-exports[`RN Codegen Flow Parser Fails with error message TWO_NATIVE_EXTENDING_TURBO_MODULE 1`] = `"File contains declarations of more than one module: Spec, Spec2. Please declare exactly one module in this file."`;
+exports[`RN Codegen Flow Parser Fails with error message TWO_NATIVE_EXTENDING_TURBO_MODULE 1`] = `"Module NativeSampleTurboModule: Every NativeModule spec file must declare exactly one NativeModule Flow interface. This file declares 2: 'Spec', and 'Spec2'. Please remove the extraneous Flow interface declarations."`;
 
 exports[`RN Codegen Flow Parser Fails with error message TWO_NATIVE_MODULES_EXPORTED_WITH_DEFAULT 1`] = `"File neither contains a module declaration, nor a component declaration. For module declarations, please make sure your file has an InterfaceDeclaration extending TurboModule. For component declarations, please make sure your file has a default export calling the codegenNativeComponent<Props>(...) macro."`;
 

packages/react-native-codegen/src/parsers/flow/modules/errors.js

@@ -23,12 +23,33 @@ class MisnamedModuleFlowInterfaceParserError extends ParserError {
   }
 }
 
-class ModuleFlowInterfaceNotParserError extends ParserError {
+class ModuleFlowInterfaceNotFoundParserError extends ParserError {
   constructor(hasteModuleName: string, ast: $FlowFixMe) {
     super(
       hasteModuleName,
       ast,
-      `Module ${hasteModuleName}: No Flow interfaces extending TurboModule were detected in this NativeNativeModule spec.`,
+      'No Flow interfaces extending TurboModule were detected in this NativeModule spec.',
+    );
+  }
+}
+
+class MoreThanOneModuleFlowInterfaceParserError extends ParserError {
+  constructor(
+    hasteModuleName: string,
+    flowModuleInterfaces: $ReadOnlyArray<$FlowFixMe>,
+    names: $ReadOnlyArray<string>,
+  ) {
+    const finalName = names[names.length - 1];
+    const allButLastName = names.slice(0, -1);
+    const quote = x => `'${x}'`;
+
+    const nameStr =
+      allButLastName.map(quote).join(', ') + ', and ' + quote(finalName);
+
+    super(
+      hasteModuleName,
+      flowModuleInterfaces,
+      `Every NativeModule spec file must declare exactly one NativeModule Flow interface. This file declares ${names.length}: ${nameStr}. Please remove the extraneous Flow interface declarations.`,
     );
   }
 }
@@ -294,7 +315,8 @@ class IncorrectModuleRegistryCallArgumentTypeParserError extends ParserError {
 module.exports = {
   IncorrectlyParameterizedFlowGenericParserError,
   MisnamedModuleFlowInterfaceParserError,
-  ModuleFlowInterfaceNotParserError,
+  ModuleFlowInterfaceNotFoundParserError,
+  MoreThanOneModuleFlowInterfaceParserError,
   UnnamedFunctionParamParserError,
   UnsupportedArrayElementTypeAnnotationParserError,
   UnsupportedFlowGenericParserError,

packages/react-native-codegen/src/parsers/flow/modules/index.js

@@ -31,7 +31,8 @@ const {unwrapNullable, wrapNullable} = require('./utils');
 const {
   IncorrectlyParameterizedFlowGenericParserError,
   MisnamedModuleFlowInterfaceParserError,
-  ModuleFlowInterfaceNotParserError,
+  ModuleFlowInterfaceNotFoundParserError,
+  MoreThanOneModuleFlowInterfaceParserError,
   UnnamedFunctionParamParserError,
   UnsupportedArrayElementTypeAnnotationParserError,
   UnsupportedFlowGenericParserError,
@@ -580,8 +581,16 @@ function buildModuleSchema(
     );
   });
 
-  if (moduleInterfaceNames.length !== 1) {
+  if (moduleInterfaceNames.length === 0) {
-    throw new ModuleFlowInterfaceNotParserError(hasteModuleName, ast);
+    throw new ModuleFlowInterfaceNotFoundParserError(hasteModuleName, ast);
+  }
+
+  if (moduleInterfaceNames.length > 1) {
+    throw new MoreThanOneModuleFlowInterfaceParserError(
+      hasteModuleName,
+      moduleInterfaceNames.map(name => types[name]),
+      moduleInterfaceNames,
+    );
   }
 
   const [moduleInterfaceName] = moduleInterfaceNames;