refactor: stop parsing functions to extract dependencies

closes #77
BREAKING CHANGE: will now need to explicitly delcare dependencies or use TS inference

CHANGELOG.md

@@ -4,6 +4,11 @@ Change Log
 - global dependencies such as `Window` and `Document` are now automatically resolved (unless you register your own dependency of the same name)
 - you can now control dependency resolution with config flags `nodeModules` and `globals`
 - you can also specify whether dependencies should be optional-by-default with an `optional` flag
+- dependencies are no longer determined by reading the factory function. Either use `TS` inference, or explicitly pass an array of deps
+
+#### Breaking Changes
+- if you attempt to resolve a global like `Window` without registering it first, rather than throw an error, you will now get the global variable
+- You can no longer do `jpex.factory('foo', (depA, depB) => { ... })` as we no longer parse the function and extract the dependencies
 
 ### 3.5.0
 - add some deprecation warnings for pre-4.0.0 changes

src/encase.ts

@@ -1,21 +1,20 @@
 import { JpexInstance, Dependency, AnyFunction } from './types';
-import { extractParameters } from './utils';
 import { allResolved, resolveDependencies } from './resolver';
 
-const encase = (
+const encase = <F extends AnyFunction, G extends AnyFunction<F>>(
   jpex: JpexInstance,
-  _deps: string[],
+  _deps: any,
   _fn?: any,
 ): any => {
-  const [ dependencies, fn ] = ((): [ Dependency[], any ] => {
+  const [ dependencies, fn ] = ((): [ Dependency[], G ] => {
     if (typeof _deps === 'function') {
-      return [ extractParameters(_deps), _deps ];
+      return [ [], _deps ];
     }
     return [ _deps, _fn ];
   })();
   let result: AnyFunction;
 
-  const encased = function(...args: Parameters<any>) {
+  const encased = function(...args: Parameters<F>) {
     /* eslint-disable no-invalid-this */
     if (result && allResolved(jpex, dependencies)) {
       return result.apply(this, args);

src/registers/factory.ts

@@ -1,6 +1,6 @@
 import { JpexInstance, Factory } from '../types';
 import wrapper, { Wrapper } from './wrapper';
-import { extractParameters, isString, isFunction } from '../utils';
+import { isString, isFunction } from '../utils';
 
 function factory(
   jpex: JpexInstance,
@@ -21,7 +21,7 @@ function factory(
   if (dependencies) {
     dependencies = [].concat(dependencies);
   } else {
-    dependencies = extractParameters(fn);
+    dependencies = [];
   }
   if (!dependencies.length) {
     dependencies = null;

src/registers/service.ts

@@ -1,5 +1,5 @@
 import { JpexInstance } from '../types';
-import { extractParameters, instantiate, isFunction } from '../utils';
+import { instantiate, isFunction } from '../utils';
 
 function service(
   jpex: JpexInstance,
@@ -18,7 +18,7 @@ function service(
   if (dependencies) {
     dependencies = [].concat(dependencies);
   } else {
-    dependencies = extractParameters(fn);
+    dependencies = [];
   }
 
   function factory(...args: any[]) {

src/utils/index.ts

@@ -1,5 +1,3 @@
-import { AnyFunction } from '../types';
-
 const getType = (obj: any) => Object.prototype.toString.call(obj);
 export const isObject = (obj: any): obj is object => getType(obj) === '[object Object]';
 
@@ -36,42 +34,6 @@ export const unsafeRequire = (target: string) => {
   return new Function('require', 'target', 'return require.main.require(target)')(require, target);
 };
 
-const REG_COMMENTS = /\/\/(.*?)\n|\/\*([\S\s]*?)\*\//g;
-export const extractParameters = (fn: AnyFunction) => {
-  const CHR_OPEN = '(';
-  const CHR_CLOSE = ')';
-  const CHR_ARROW = '=>';
-  const CHR_DELIMETER = ',';
-
-  let str = fn.toString();
-
-  // Remove comments
-  str = str.replace(REG_COMMENTS, '');
-
-  // Find the start and end of the parameters
-  const open = str.indexOf(CHR_OPEN);
-  const close = str.indexOf(CHR_CLOSE);
-  const arrow = str.indexOf(CHR_ARROW);
-
-  // Arrow functions may or may not contain brackets
-  if (arrow > -1 && (arrow < open || open < 0)) {
-    str = str.substring(0, arrow).trim();
-    if (!str) {
-      return [];
-    }
-    return [ str ];
-  }
-
-  // Pull out the parameters
-  str = str.substring(open + 1, close);
-
-  if (!str) {
-    return [];
-  }
-
-  return str.split(CHR_DELIMETER).map((s) => s.trim());
-};
-
 interface GetLast {
   (str: string): string,
   <T>(arr: T[]): T,