fix: hack for babel < 6 so that breakpoints do work

It fixes #627, but AFAIK there is badly no way of doing a test for that

src/postprocess.ts

@@ -26,6 +26,25 @@ function importBabelDeps() {
  if (babel) return; // tslint:disable-line
  // we must use babel until we handle hoisting of jest.mock() internally
  babel = importBabelCore();
+
+ // HACK: there is an issue still open in babel 6, this is a hack to bypass it
+ // and fix our issue #627
+ // Issue in babel: https://github.com/babel/babel/issues/6577
+ if (babel.version && parseInt(babel.version.split('.')[0], 10) === 6) {
+ const File = require('babel-core/lib/transformation/file/index.js').File;
+ File.prototype.initOptions = (original => {
+ return function(opt) {
+ const before = opt.sourceMaps;
+ const result = original.apply(this, arguments);
+ if (opt.sourceMaps != null && opt.sourceMaps !== result.sourceMaps) {
+ result.sourceMaps = opt.sourceMaps;
+ }
+ return result;
+ };
+ })(File.prototype.initOptions);
+ }
+ // end of HACK
+
  istanbulPlugin = importBabelPluginIstanbul();
  jestPreset = importBabelPresetJest();
 }