Add temperature units support

app/static/app/js/classes/Units.js

@@ -3,7 +3,8 @@ import { _ } from './gettext';
 const types = {
     LENGTH: 1,
     AREA: 2,
-    VOLUME: 3
+    VOLUME: 3,
+    TEMPERATURE: 4
 };
 
 const units = {
@@ -139,6 +140,26 @@ const units = {
         round: 4,
         label: _("Cubic Yards"),
         type: types.VOLUME
+    },
+    celsius:{
+        conversion:{
+            forward: celsius => celsius,
+            backward: celsius => celsius
+        },
+        abbr: '°C',
+        round: 1,
+        label: _("Celsius"),
+        type: types.TEMPERATURE
+    },
+    fahrenheit:{
+        conversion: {
+            forward: celsius => (9.0 / 5.0) * celsius + 32.0,
+            backward: fahrenheit => (fahrenheit - 32.0) * (5.0 / 9.0)
+        },
+        abbr: '°F',
+        round: 1,
+        label: _("Fahrenheit"),
+        type: types.TEMPERATURE
     }
 };
 
@@ -175,6 +196,7 @@ class UnitSystem{
     lengthUnit(meters, opts = {}){ throw new Error("Not implemented"); }
     areaUnit(sqmeters, opts = {}){ throw new Error("Not implemented"); }
     volumeUnit(cbmeters, opts = {}){ throw new Error("Not implemented"); }
+    temperatureUnit(celsius, opts = {}){ throw new Error("Not implemented"); }
 
     getName(){ throw new Error("Not implemented"); }
     getKey(){ throw new Error("Not implemented"); }
@@ -209,6 +231,15 @@ class UnitSystem{
         const val = unit.factor * cbmeters;
         return new ValueUnit(val, unit);
     }
+
+    temperature(celsius, opts = {}){
+        celsius = parseFloat(celsius);
+        if (isNaN(celsius)) return NanUnit();
+
+        const unit = this.temperatureUnit(celsius, opts);
+        const val = unit.conversion.forward(celsius);
+        return new ValueUnit(val, unit);
+    }
 };
 
 function toMetric(valueUnit, unit){
@@ -221,13 +252,23 @@ function toMetric(valueUnit, unit){
     }
     if (isNaN(value)) return NanUnit();
 
-    const val = value / unit.factor;
+    let val;
+    if (unit.factor !== undefined){
+        val = value / unit.factor;
+    }else if (unit.conversion !== undefined){
+        val = unit.conversion.backward(value);
+    }else{
+        throw new Error(`No unit factor or conversion: ${unit.type}`);
+    }
+
     if (unit.type === types.LENGTH){
         return new ValueUnit(val, units.meters);
     }else if (unit.type === types.AREA){
         return new ValueUnit(val, unit.sqmeters);
     }else if (unit.type === types.VOLUME){
         return new ValueUnit(val, unit.cbmeters);
+    }else if (unit.type === types.TEMPERATURE){
+        return new ValueUnit(val, units.celsius);
     }else{
         throw new Error(`Unrecognized unit type: ${unit.type}`);
     }
@@ -261,6 +302,10 @@ class MetricSystem extends UnitSystem{
     volumeUnit(cbmeters, opts = {}){
         return units.cbmeters;
     }
+
+    temperatureUnit(celsius, opts = {}){
+        return units.celsius;
+    }
 }
 
 class ImperialSystem extends UnitSystem{
@@ -316,6 +361,10 @@ class ImperialSystem extends UnitSystem{
     volumeUnit(cbmeters, opts = {}){
         return this.cbyards();
     }
+
+    temperatureUnit(celsius, opts = {}){
+        return units.fahrenheit;
+    }
 }
 
 class ImperialUSSystem extends ImperialSystem{

app/static/app/js/components/tests/Units.test.jsx

@@ -50,6 +50,15 @@ describe('Metric system', () => {
     });
 
     expect(metric.area(11005.09, { fixedUnit: true }).toString({precision: 1})).toBe("11,005.1 m²");
+
+    const temperatures = [
+      [1, "1 °C"],
+      [100.255, "100.3 °C"]
+    ];
+
+    temperatures.forEach(v => {
+      expect(metric.temperature(v[0]).toString()).toBe(v[1]);
+    });
   })
 });
 
@@ -98,6 +107,15 @@ describe('Imperial systems', () => {
     });
 
     expect(imperial.area(9999, { fixedUnit: true }).toString({precision: 1})).toBe("107,628.3 ft²");
+
+    const temperatures = [
+      [1, "33.8 °F"],
+      [100.255, "212.5 °F"]
+    ];
+
+    temperatures.forEach(v => {
+      expect(imperial.temperature(v[0]).toString()).toBe(v[1]);
+    });
   });
 });
 
@@ -118,5 +136,13 @@ describe('Metric conversion', () => {
 
     expect(toMetric(km).value).toBe(2000);
     expect(toMetric(mi).value).toBe(3220);
+
+    const celsius = metric.temperature(50);
+    const fahrenheit = imperial.temperature(50);
+
+    expect(celsius.unit.abbr).toBe("°C");
+    expect(fahrenheit.unit.abbr).toBe("°F");
+    expect(toMetric(celsius).value).toBe(50);
+    expect(toMetric(fahrenheit).value).toBe(50);
   });
 });