observable.map.replace doesn't seem to work for [[k,v], [k,v]] form

Welcome to MobX. Please provide as much relevant information as possible!

I have a: 3. [ ✔️] Issue:

• Elaborate on your issue. What behavior did you expect?

        `
            const newMap = [['a', 'hi'], ['b', 'hello']]
   
            @action setMyMap(myNewMap) {
                if(this.myMap)
                      this.myMap.replace(myMap) //This is not triggering re-render
                else
                      this.myMap = observable.map(myNewMap)
             }
  
             this.setMyMap(newMap);
        `
      
         It started working when instead of    `this.myMap.replace(myMap)`, I did a
         `
              this.myMap.clear()
              this.myMap.merge(myNewMap)
         `
  

• State the versions of MobX and relevant libraries. Which browser / node / … version?

  MobX - 5.7.0

[CubedEye]

@mweststrate Can confirm this is still a bug in 5.8.0. We are using replace() in a sorting context to reorder a map of models by their ids.

Calling _setModels with a reordered array using replace() doesn’t trigger a rerender:

_models = observable.map(new Map(), { deep: false });
_setModels(modelsArray) {
    const newModels = modelsArray.map(model => [model.id, model]);
    this._models.replace(newModels);
}

However, this does correctly trigger the rerender:

_models = observable.map(new Map(), { deep: false });
_setModels(modelsArray) {
    const newModels = modelsArray.map(model => [model.id, model]);
    this._models.clear();
    this._models.merge(newModels);
}

Full disclosure, we’re in the process of upgrading from 3.3.1 to 5.8.0 where this previously worked because the implementation was just .clear() and .merge(). Would appear that calling replace() with a reordered list of values, no longer does anything because it’s not removing or adding any keys, which would be fine except the documentation still says:

Replaces the entire contents of this map with the provided values. Short hand for .clear().merge(values)

[fi3ework]

this.myMap.replace(myMap) //This is not triggering re-render

you may mean to pass myNewMap, but you passed myMap indeed?

and your second way which works passed into myNewMap

this.myMap.clear()
this.myMap.merge(myNewMap)