Angular Ivy detection logic.

angular-ivy-detection.ts

import {
  Type,
  ɵNG_COMP_DEF,
  ɵNG_DIR_DEF,
  ɵNG_MOD_DEF,
  ɵNG_PIPE_DEF,
} from '@angular/core';

function isIvy(): boolean {
  const ng: any = ((self || global || window) as any).ng;

  return ng === undefined
    || ng.getComponent !== undefined
    || ng.applyChanges !== undefined;
}

function isIvyComponent(componentType: Type<any>): boolean {
  return (componentType as any)[ɵNG_COMP_DEF] !== undefined;
}

function isIvyDirective(directiveType: Type<any>): boolean {
  return (directiveType as any)[ɵNG_DIR_DEF] !== undefined;
}

function isIvyModule(moduleType: Type<any>): boolean {
  return (moduleType as any)[ɵNG_MOD_DEF] !== undefined;
}

function isIvyPipe(pipeType: Type<any>): boolean {
  return (pipeType as any)[ɵNG_PIPE_DEF] !== undefined;
}

You may want to include your table:

Rendering engine, Angular version, environment	window.ngDevMode	window.ng	MyPipe
View Engine 8 dev	object	object with properties coreTokens & probe	class with static property __annotations__ (array)
View Engine 8 prod	undefined	object with properties coreTokens & probe	class with no own static properties
View Engine 9 dev	object	object with properties coreTokens & probe	class with no own static properties
View Engine 9 prod	undefined	object with properties coreTokens & probe	class with no own static properties
Ivy 8 dev	object	undefined	class with static properties ngPipeDef (object) & decorators (array)
Ivy 8 prod	undefined	undefined	class with static property ngPipeDef (object)
Ivy 9 dev	object	object with properties getComponent & markDirty	class with static property ɵpipe (object)
Ivy 9 prod	undefined	undefined	class with static property ɵpipe (object)

And info on how to use the table:

For Angular versions 8 and 9  

• View Engine if window.ng is an object with property probe.
• Ivy if pipe class has own static property ngPipeDef (version 8) or ɵpipe (version 9), both objects.  
• Development mode if window.ngDevMode is an object.
• Production mode if window.ngDevMode is undefined or false.

As file to the above gist

You also may include:

function isIvy(): boolean {
  const ng: any = ((self || global || window) as any).ng;

  return ng === undefined || ng.probe === undefined;
}

"ng unavailable?" = Ivy.
"ng available with probe property?" = View Engine.

Thanks for the suggestions, Michael. You left out the header of the table though 😄

Updated. Sry for the mistake!

Also here the tests I created, just in case it helps. :)

Functions:

export function getGlobalThis() {
  return (self || global || window) as any;
}

export function isIvy(): boolean {
  const ng: any = getGlobalThis().ng;

  // Is the global ng object is unavailable?
  // ng === undefined in Ivy production mode
  // View Engine has the ng object both in development mode and production mode.
  return (
    ng === undefined ||
    // in case we are in dev mode in ivy
    // `probe` property is available on ng object we use View Engine.
    ng.probe === undefined
  );
}

Tests:

describe('isIvy', () => {
  describe('in ViewEngine Angular 8 + 9', () => {
    it('should return false if ng is defined with probe', () => {
      getGlobalThis().ng = { probe: true };
      expect(isIvy()).toBe(false);
    });
  });
  describe('in Ivy Angular 9', () => {
    it('should return true if ng is undefined', () => {
      getGlobalThis().ng = undefined;
      expect(isIvy()).toBe(true);
    });

    it('should return true if ng.probe is available', () => {
      getGlobalThis().ng = { probe: undefined };
      expect(isIvy()).toBe(true);
    });
  });
});

if ng.probe is set

Should be rephrased 😊

ng.markDirty changed name to ng.applyChanges in v9.

Changed to 'is available'

But the description doesn't match what's tested. It's backwards. If probe is defined, we're in View Engine.

Maybe it's too late for me, but isn't this

it(' isIvy should return false if ng is defined with probe', () => {
      getGlobalThis().ng = { probe: true };
      expect(isIvy()).toBe(false);
    });

correct as

If probe is defined, we're in View Engine.

and

 it('should return true if ng is undefined', () => {
      getGlobalThis().ng = undefined;
      expect(isIvy()).toBe(true);
    });

and

    it('should return true if ng.probe is available', () => {
      getGlobalThis().ng = { probe: undefined };
      expect(isIvy()).toBe(true);
    });
  });

is also correct as ng is undefined or ng is defined but probe is undefined?

"should return true if ng.probe is undefined"

See, it was too late. haha.

Thanks! Updated it.