Updated slice reducers to modern rtk syntax.

unit-conversion/src/features/number-input-field/numberInputFieldSlice.js

@@ -8,10 +8,7 @@ const numberInputFieldSlice = createSlice({
   reducers: {
     setNumberOfUnits: (state, action) => {
       const numToConvert = action.payload;
-      return {
-        ...state,
-        numberToConvert: numToConvert,
-      };
+      state.numberToConvert = numToConvert;
     },
   },
 });

unit-conversion/src/features/unit-selector/unitSelectorSlice.js

@@ -10,17 +10,11 @@ const unitSelectorSlice = createSlice({
     // The action payload should have the unit to switch to with the in or out
     setCurrentInputUnit: (state, action) => {
       const newUnit = action.payload;
-      return {
-        ...state,
-        currentInputUnit: newUnit,
-      };
+      state.currentInputUnit = newUnit;
     },
     setCurrentOutputUnit: (state, action) => {
       const newUnit = action.payload;
-      return {
-        ...state,
-        currentOutputUnit: newUnit,
-      };
+      state.currentOutputUnit = newUnit;
     },
   },
 });