Allow generic type definitions & non-default exports

packages/ts-interface-generator/README.md

@@ -95,18 +95,75 @@ This is a problem for application code using controls developed in TypeScript as
 
 This tool scans all TypeScript source files for <b>top-level definitions of classes</b> inheriting from `sap.ui.base.ManagedObject` (in most cases those might be sub-classes of `sap.ui.core.Control`, so they will be called "controls" for simplicity).
 
-For any such control, the metadata is parsed, analyzed, and a new TypeScript file is constructed, which contains an interface declaration with the methods generated by UI5 at runtime.
+For any such control, the metadata is parsed, analyzed, and a new TypeScript file is constructed, which contains an interface declaration with the methods generated by UI5 at runtime. This generated interface gets merged with the already existing code using TypeScripts [Declaration Merging](https://www.typescriptlang.org/docs/handbook/declaration-merging.html) concept.
 
 Unfortunately these separate interface declarations cannot define new constructors (see e.g. [this related TS issue](https://github.com/microsoft/TypeScript/issues/2957)). Hence those must be manually added to each control (one-time effort, pasting 3 lines of code). The interface generator writes the required lines to the console.
 
 Oh, and the tool itself is implemented in TypeScript because TypeScript makes development more efficient. ;-)
 
+## Features
+
+### Handling `default` and named exports
+
+In order that the Declaration Merging of TypeScript works, the modifiers of the generated interface has to match the parsed UI5 artifact.
+- **Named export:**
+  ```typescript
+  export class MyCustomControl extends Control {
+	...
+  }
+  ```
+
+  becomes
+
+  ```typescript
+  export interface MyCustomControl {
+	...
+  }
+  ```
+
+- **Default export:**
+  ```typescript
+  export default abstract class MyAbstractControl extends Control {
+	...
+  }
+  ```
+
+  becomes
+
+  ```typescript
+  export default interface MyAbstractControl {
+	...
+  }
+  ```
+
+### Generics
+
+This tool also supports generic classes which extending `ManagedObject` class. In order to enable the Declaration Merging of TypeScript the generic type parameters needs to be incooperated into the generated interface declaration.
+It takes care that types used to constrain the generic type parameter are imported in the generated interface if required.
+
+```typescript
+export interface ICommonListOptions {
+	mode: 'ul' | 'ol';
+}
+
+export default abstract class MyList<TListOptions extends ICommonListOptions> {
+	...
+}
+```
+
+becomes
+
+```typescript
+export default interface MyList<TListOptions extends ICommonListOptions> {
+	...
+}
+```
+
 ## TODO
 
 - copy the original API documentation to the generated methods
 - make sure watch mode does it right (also run on deletion? Delete interfaces before-creating? Only create interfaces for updated files?)
 - consider further information like deprecation etc.
-- it is probably required to check whether the control class being handled is the default export or a named export. Right now it is assumed that it is the default export. Other cases are not tested and likely not working.
 - ...
 
 ## Support

packages/ts-interface-generator/src/astGenerationHelper.ts

@@ -268,6 +268,126 @@ function createBindingStringTypeNode() {
   );
 }
 
+function generateGenericTypeImports(
+  sourceFile: ts.SourceFile,
+  classDeclaration: ts.ClassDeclaration,
+  statements: ts.Statement[],
+  requiredImports: RequiredImports
+): ts.Statement[] {
+  const { typeParameters } = classDeclaration;
+  const requiredGenericTypeImports: ts.Statement[] = [];
+
+  if (!typeParameters || typeParameters?.length === 0) {
+    return requiredGenericTypeImports;
+  }
+
+  const existingImportsInSourceFile: {
+    [name: string]: { statement: ts.ImportDeclaration; exportName?: string };
+  } = {};
+
+  for (const statement of sourceFile.statements) {
+    if (ts.isImportDeclaration(statement)) {
+      if (statement.importClause) {
+        const { name, namedBindings } = statement.importClause;
+
+        if (name) {
+          existingImportsInSourceFile[name.getText()] = { statement };
+        }
+
+        if (namedBindings) {
+          namedBindings.forEachChild((node) => {
+            if (ts.isImportSpecifier(node)) {
+              const typeName = node.name.getText();
+              let exportName = typeName;
+
+              if (node.propertyName) {
+                exportName = node.propertyName.getText();
+              }
+
+              existingImportsInSourceFile[typeName] = { statement, exportName };
+            }
+          });
+        }
+      }
+    }
+  }
+
+  for (const typeParameter of typeParameters) {
+    if (typeParameter.constraint) {
+      const typeName = typeParameter.constraint.getText();
+
+      if (nameIsUsed(typeName, requiredImports)) {
+        // import is already created
+        continue;
+      } else if (
+        Object.prototype.hasOwnProperty.call(
+          existingImportsInSourceFile,
+          typeName
+        )
+      ) {
+        const { statement, exportName } = existingImportsInSourceFile[typeName];
+
+        const moduleName = statement.moduleSpecifier.getText();
+        const moduleSpecifierClone = factory.createStringLiteral(
+          moduleName.substring(1, moduleName.length - 1)
+        );
+
+        let importClause: ts.ImportClause;
+        const typeNameIdentifier = factory.createIdentifier(typeName);
+
+        if (!exportName) {
+          importClause = factory.createImportClause(
+            true,
+            typeNameIdentifier,
+            undefined
+          );
+        } else {
+          const propertyName =
+            typeName !== exportName
+              ? factory.createIdentifier(exportName)
+              : undefined;
+
+          let importSpecifier: ts.ImportSpecifier;
+
+          // TODO: Use a method to check for versions
+          if (parseFloat(ts.version) >= 4.5) {
+            // @ts-ignore after 4.5, createImportSpecifier got a third parameter (in the beginning!). This code shall work with older and newer versions, but as the compile-time error check is considering either <4.5 or >=4.5, one of these lines is recognized as error
+            importSpecifier = factory.createImportSpecifier(
+              true,
+              propertyName,
+              typeNameIdentifier
+            );
+          } else {
+            // @ts-ignore after 4.5, createImportSpecifier got a third parameter (in the beginning!). This code shall work with older and newer versions, but as the compile-time error check is considering either <4.5 or >=4.5, one of these lines is recognized as error
+            importSpecifier = factory.createImportSpecifier(
+              propertyName,
+              typeNameIdentifier
+            );
+          }
+
+          importClause = factory.createImportClause(
+            false,
+            undefined,
+            factory.createNamedImports([importSpecifier])
+          );
+        }
+
+        const clone = factory.createImportDeclaration(
+          statement.decorators,
+          statement.modifiers,
+          importClause,
+          moduleSpecifierClone,
+          statement.assertClause
+        );
+
+        requiredGenericTypeImports.push(clone);
+      }
+    }
+  }
+
+  return requiredGenericTypeImports;
+}
+
 function printConstructorBlockWarning(
   settingsTypeName: string,
   className: string,
@@ -1161,6 +1281,7 @@ function createConstructorBlock(settingsTypeName: string) {
 export {
   generateMethods,
   generateSettingsInterface,
+  generateGenericTypeImports,
   addLineBreakBefore,
   createConstructorBlock,
 };

packages/ts-interface-generator/src/interfaceGenerationHelper.ts

@@ -7,6 +7,7 @@ import {
   generateMethods,
   generateSettingsInterface,
   addLineBreakBefore,
+  generateGenericTypeImports,
 } from "./astGenerationHelper";
 import astToString from "./astToString";
 import log from "loglevel";
@@ -43,6 +44,8 @@ const interestingBaseSettingsClasses: {
   '"sap/ui/core/Control".$ControlSettings': "$ControlSettings",
 };
 
+const interfaceIncompatibleModifiers = new Set([ts.SyntaxKind.AbstractKeyword]);
+
 /**
  * Checks the given source file for any classes derived from sap.ui.base.ManagedObject and generates for each one an interface file next to the source file
  * with the name <className>.gen.d.ts
@@ -424,13 +427,15 @@ function generateInterface(
   {
     sourceFile,
     className,
+    classDeclaration,
     settingsTypeFullName,
     interestingBaseClass,
     constructorSignaturesAvailable,
     metadata,
   }: {
     sourceFile: ts.SourceFile;
     className: string;
+    classDeclaration: ts.ClassDeclaration;
     settingsTypeFullName: string;
     interestingBaseClass:
       | "ManagedObject"
@@ -479,7 +484,8 @@ function generateInterface(
   const moduleName = path.basename(fileName, path.extname(fileName));
   const ast = buildAST(
     classInfo,
-    sourceFile.fileName,
+    sourceFile,
+    classDeclaration,
     constructorSignaturesAvailable,
     moduleName,
     settingsTypeFullName,
@@ -495,12 +501,15 @@ function generateInterface(
 
 function buildAST(
   classInfo: ClassInfo,
-  classFileName: string,
+  sourceFile: ts.SourceFile,
+  classDeclaration: ts.ClassDeclaration,
   constructorSignaturesAvailable: boolean,
   moduleName: string,
   settingsTypeFullName: string,
   allKnownGlobals: GlobalToModuleMapping
 ) {
+  const { fileName: classFileName } = sourceFile;
+
   const requiredImports: RequiredImports = {};
   const methods = generateMethods(classInfo, requiredImports, allKnownGlobals);
   if (methods.length === 0) {
@@ -519,14 +528,24 @@ function buildAST(
 
   const statements: ts.Statement[] = getImports(requiredImports);
 
+  const requiredGenericTypeImports = generateGenericTypeImports(
+    sourceFile,
+    classDeclaration,
+    statements,
+    requiredImports
+  );
+
+  if (requiredGenericTypeImports.length > 0) {
+    statements.push(...requiredGenericTypeImports);
+  }
+
   const myInterface = factory.createInterfaceDeclaration(
     undefined,
-    [
-      factory.createModifier(ts.SyntaxKind.ExportKeyword),
-      factory.createModifier(ts.SyntaxKind.DefaultKeyword),
-    ],
+    classDeclaration.modifiers?.filter(
+      (modifier) => !interfaceIncompatibleModifiers.has(modifier.kind)
+    ),
     classInfo.name,
-    undefined,
+    classDeclaration.typeParameters,
     undefined,
     methods
   );

packages/ts-interface-generator/src/test/generateInterfaceWithGenerics.test.ts

@@ -0,0 +1,72 @@
+import ts from "typescript";
+import { generateInterfaces } from "../interfaceGenerationHelper";
+import { initialize } from "../typeScriptEnvironment";
+
+test("Generating the interface for a class using generics", () => {
+  const expected = `import { PropertyBindingInfo } from "sap/ui/base/ManagedObject";
+import { $ManagedObjectSettings } from "sap/ui/base/ManagedObject";
+
+declare module "./SampleGenericManagedObject" {
+
+    /**
+     * Interface defining the settings object used in constructor calls
+     */
+    interface $SampleGenericManagedObjectSettings extends $ManagedObjectSettings {
+        text?: string | PropertyBindingInfo;
+    }
+
+    export default interface SampleGenericManagedObject<TOptions, TOptions2> {
+
+        // property: text
+        getText(): string;
+        setText(text: string): this;
+    }
+}
+`;
+
+  function onTSProgramUpdate(
+    program: ts.Program,
+    typeChecker: ts.TypeChecker,
+    changedFiles: string[], // is an empty array in non-watch case; is at least one file in watch case
+    allKnownGlobals: {
+      [key: string]: { moduleName: string; exportName?: string };
+    }
+  ) {
+    // files recognized as "real" app source files should be exactly one: SampleGenericManagedObject.ts
+    const sourceFiles: ts.SourceFile[] = program
+      .getSourceFiles()
+      .filter((sourceFile) => {
+        if (
+          sourceFile.fileName.indexOf("@types") === -1 &&
+          sourceFile.fileName.indexOf("node_modules/") === -1 &&
+          sourceFile.fileName.indexOf(".gen.d.ts") === -1
+        ) {
+          return true;
+        }
+      });
+    expect(sourceFiles).toHaveLength(1);
+    expect(sourceFiles[0].fileName).toMatch(/.*SampleGenericManagedObject.ts/);
+
+    // this function will be called with the resulting generated interface text - here the big result check occurs
+    function checkResult(
+      sourceFileName: string,
+      className: string,
+      interfaceText: string
+    ) {
+      expect(sourceFileName).toMatch(/.*SampleGenericManagedObject.ts/);
+      expect(className).toEqual("SampleGenericManagedObject");
+
+      expect(interfaceText).toEqual(expected);
+    }
+
+    // trigger the interface generation - the result will be given to and checked in the function above
+    generateInterfaces(
+      sourceFiles[0],
+      typeChecker,
+      allKnownGlobals,
+      checkResult
+    );
+  }
+
+  initialize("./tsconfig-testgenerics.json", onTSProgramUpdate, {});
+});