Is there code generation API for TypeScript?

Try ts-morph. Only been working with it for about an hour but it seems really capable.

import {Project, Scope, SourceFile} from "ts-morph";

const project = new Project();
const sourceFile = project.createSourceFile(`./target/file.ts`);

const classDeclaration = sourceFile.addClass({
    name: 'SomeClass'
});

const constr = classDeclaration.addConstructor({});

constr.setBodyText('this.myProp = myProp');

classDeclaration.addProperty({
    name: 'myProp',
    type: 'string',
    initializer: 'hello world!',
    scope: Scope.Public
});
sourceFile.formatText();
console.log(sourceFile.getText());

Is there something simmilar for typescript

Not yet, but the TypeScript team is opening up the emitter (what is that) for plugins that would make this a supported scenario : https://github.com/Microsoft/TypeScript/issues/5595


as of Oct-2018 You could use standard TypeScript API for that

import ts = require("typescript");

function makeFactorialFunction() {
  const functionName = ts.factory.createIdentifier("factorial");
  const paramName = ts.factory.createIdentifier("n");
  const parameter = ts.factory.createParameterDeclaration(
    /*decorators*/ undefined,
    /*modifiers*/ undefined,
    /*dotDotDotToken*/ undefined,
    paramName
  );

  const condition = ts.factory.createBinaryExpression(
    paramName,
    ts.SyntaxKind.LessThanEqualsToken,
    ts.factory.createNumericLiteral(1)
  );

  const ifBody = ts.factory.createBlock(
    [ts.factory.createReturnStatement(ts.factory.createNumericLiteral(1))],
    /*multiline*/ true
  );
  const decrementedArg = ts.factory.createBinaryExpression(
    paramName,
    ts.SyntaxKind.MinusToken,
    ts.factory.createNumericLiteral(1)
  );
  const recurse = ts.factory.createBinaryExpression(
    paramName,
    ts.SyntaxKind.AsteriskToken,
    ts.factory.createCallExpression(functionName, /*typeArgs*/ undefined, [decrementedArg])
  );
  const statements = [ts.factory.createIfStatement(condition, ifBody), ts.factory.createReturnStatement(recurse)];

  return ts.factory.createFunctionDeclaration(
    /*decorators*/ undefined,
    /*modifiers*/ [ts.factory.createToken(ts.SyntaxKind.ExportKeyword)],
    /*asteriskToken*/ undefined,
    functionName,
    /*typeParameters*/ undefined,
    [parameter],
    /*returnType*/ ts.factory.createKeywordTypeNode(ts.SyntaxKind.NumberKeyword),
    ts.factory.createBlock(statements, /*multiline*/ true)
  );
}

const resultFile = ts.createSourceFile(
  "someFileName.ts",
  "",
  ts.ScriptTarget.Latest,
  /*setParentNodes*/ false,
  ts.ScriptKind.TS
);
const printer = ts.createPrinter({
  newLine: ts.NewLineKind.LineFeed
});
const result = printer.printNode(
  ts.EmitHint.Unspecified,
  makeFactorialFunction(),
  resultFile
);

console.log(result);

Taken here: https://github.com/Microsoft/TypeScript/wiki/Using-the-Compiler-API#user-content-creating-and-printing-a-typescript-ast

Tags:

Code Generation

T4

Roslyn

Typescript

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