find-side-effects.js

var glob = require("glob");
const ts = require("typescript");
const { readFileSync, readdirSync, statSync } = require("fs");
const { join } = require("path");
const dirs = p =>
  readdirSync(p).filter(f => statSync(join(p, f)).isDirectory());

var results = new Set();

const alldirs = dirs("[FOLDER PATH HERE]/expo/packages/");
alldirs.forEach(function(foldername) {
  const folderpath =
    "[FOLDER PATH HERE]/expo/packages/" +
    foldername +
    "/src/";
  glob(folderpath + "**/*.+(js|ts)", {}, function(er, files) {
    files.forEach(function(filename) {
      if (filename.includes("/node_modules/")) {
        return;
      }
      if (filename.includes("/__tests__/")) {
        return;
      }
      if (filename.endsWith(".web.ts") || filename.endsWith(".web.js")) {
        return;
      }
      //console.log(filename);

      const sourceFile = ts.createSourceFile(
        filename,
        readFileSync(filename).toString(),
        ts.ScriptTarget.ES6,
        false
      );
      //console.log(sourceFile);

      let result = ts.transpileModule(sourceFile.text, {
        compilerOptions: {
          module: ts.ModuleKind.CommonJS
        }
      });

      //console.log(result.outputText);

      //console.log(JSON.stringify(result));

      if (checkEsp(result.outputText)) {
        console.warn(foldername);
        results.add(foldername);
      }
    });
  });
});

function checkEsp(resulttext) {
  var esprima = require("esprima");
  var espresult = esprima.parse(resulttext).body;
  //console.log(espresult);
  //console.log(JSON.stringify(espresult[3]));

  var thisr = false;
  espresult.forEach(function(value) {
    if (
      (value.type === "ExpressionStatement" &&
        value.expression !== null &&
        value.expression.type !== null &&
        value.expression.type === "CallExpression" &&
        // Allows `export *`
        value.expression.callee.name !== "__export" &&
        // Allows `export enum` and `export type` related things
        !(
          value.expression.callee.id === null &&
          (
            (
              ((value.expression.arguments || [{}])[0].right || {}).left ||
              {}
            ).object || {}
          ).name === "exports"
        ) &&
        // Allows `Object.assign`
        !(
          (value.expression.callee.object || {}).name === "Object" &&
          (value.expression.callee.property || {}).name === "assign"
        )) ||
      value.type === "IfStatement"
    ) {
      //console.log("BOOO!");
      //console.log(value);
      thisr = true;
    }
  });

  return thisr;
}