canonicalTypeName.ts

import { createNewParserState, ParserState } from "./ParserState";
import ts from "typescript";
import { parseTypeDefinition } from "./parseTypeDefinition";

/**
 * A function that creates a unique string for a given interface or object type,
 * from a fresh parser state. This should return the same string for two semantically
 * identically types, allowing us to re-use existing helper types if the generated
 * strings match.
 **/
export const getCanonicalTypeName = (state: ParserState, type: ts.Type) => {
  const cachedName = state.canonicalTypeNames.get(type);
  if (cachedName) {
    return cachedName;
  } else {
    const tmpState = createNewParserState(state.typechecker, state.config);
    parseTypeDefinition(tmpState, "TS2PyTmpType", type);
    const result = tmpState.statements.join("\n");
    state.canonicalTypeNames.set(type, result);
    return result;
  }
};