`get` helper returns `undefined` when the key is a string containing a period

[fdeters]

🐞 Describe the Bug

Ember's get helper from @ember/helper can't handle accessing a value in an object when the key is a string with a dot in it.

E.g. applying {{ get obj 'some.key' }} to const obj = { 'some.key': 'some value' };will returnundefinedrather than'some value'`.

🔬 Minimal Reproduction

See description above and this reproduction on latest Ember: Repro on Limber

😕 Actual Behavior

Ember's get helper returns undefined when attempting to access a key that is a string containing a period.

🤔 Expected Behavior

I expect the get helper to handle accessing keys on objects just like vanilla JavaScript does. Barring that, I expect clear documentation about the different behavior.

🌍 Environment

• Ember: 6.12.0

[fdeters]

I'm guessing this is related to some desired behavior in previous versions of Ember, where resolving objects based on string paths was much more important. To me, as a relatively new Ember user (3 years), the behavior makes no obvious sense.

[ijlee2]

The behavior of {{get obj ...}} can indeed be confusing, as it doesn't exactly match obj[...] in JavaScript.

The syntax {{get obj "some.key"}} is more like obj?.['some']?.['key']. That is, if any of the values along the way isn't well-defined, Ember avoids throwing an error by treating the expression as undefined. This can be useful when obj refers to complex data, maybe retrieved from the backend, since it's harder to make early exits in a template.

If you want the value of obj['some.key'], I'd recommend defining a getter in the backing class or (with ember-source@>=4.5) a function used a helper, and referring to this getter or helper in the template. By doing so, you can make your business logic more explicit.

I do think the documentation could mention the two edge cases: keyName is a path, and keyName is a number or stringified number (i.e. {{get}} is used more like Array.at()).

• https://api.emberjs.com/ember/6.12/functions/@ember%2Fobject/get (note, isn't listed under @ember/helper)
• https://github.com/emberjs/ember.js/blob/v6.12.0-ember-source/packages/%40ember/-internals/metal/lib/property_get.ts#L102
• https://github.com/emberjs/ember.js/blob/v6.12.0-ember-source/packages/%40ember/-internals/metal/lib/property_get.ts#L145-L161

[kategengler]

As you showed in your repro, you can implement your own helper to behave like object access: https://share.glimdown.com/sbTKQnK7TRaTK121CdfrNQ

We are unlikely to change the behavior of the get helper as it has existed for an extremely long time.

I agree we could clarify in the api docs.