function isModuleDefined

[linjianhong]

I'm submitting a ...

• bug report
• feature request
• other

Current behavior:
When redefine module, orgin module lost.

Expected / new behavior:
Override a module, or do something whether the modele is defined or not.

Minimal reproduction of the problem with instructions:
none

AngularJS version: 1.x.y
all

Browser: [all]

Anything else:
before the code:

      if (requires && modules.hasOwnProperty(name)) {
        modules[name] = null;
      }

add:

      if(isBoolean(requires)){
        return modules.hasOwnProperty(name);
      }

then I can user like this:

      if(angular.module('my-module', true)){
        // codes
      }
      else{
        // codes if not exit module 'my-module'
      }

[gkalpak]

If we decided to implement this, we should not overload the angular.module() helper, but introduce a new one (e.g. angular.hasModule('<module-name>')). But given that writing your own helper is very easy (and taking into account that AngularJS is just about to enter LTS), I would lean towards not adding it. You can create it yourself like this:

angular.hasModule = function hasModule(moduleName) {
  try {
    angular.module(moduleName);
    return true;
  } catch (_ignored) {
    return false;
  }
};

[linjianhong]

In fact, I did exactly the same. It's just that this hack doesn't look elegant enough. Usually, I try not to let the code of the catch block run.
Thank you so much!