Fix bug in subcompartments

Fix minor bug in subcompartments that returned an object as population, even when there were no subcompartments.

EpiJS/model.js

@@ -79,10 +79,11 @@ class Model {
 			}
 			key = newkey
 			if (x === time - 1) {
-				var return_val = {}
+				let return_val = {}
 				for (y in this.compartments) {
+					return_val[this.compartments[y][1]] = key[this.compartments[y][1]]
 					// Check for sub-compartmnets
-					if(this.compartments[y][0].compartments && Object.keys(this.compartments[y][0].compartments).length === 0 && Object.getPrototypeOf(this.compartments[y][0].compartments) === Object.prototype) {
+					if(Object.keys(this.compartments[y][0].compartments).length !== 0) {
 						return_val[this.compartments[y][1]] = {
 							"population": key[this.compartments[y][1]],
 							"compartments": {}
@@ -91,9 +92,6 @@ class Model {
 							return_val[this.compartments[y][1]]["compartments"][z] = this.compartments[y][0].getSubData(z, key)
 						}
 					}
-					else {
-						return_val[this.compartments[y][1]] = key[this.compartments[y][1]]
-					}
 				}
 				return return_val
 			}

index.js

@@ -0,0 +1,21 @@
+var x = {
+    x: {
+        x: {
+            x: 10
+        },
+        y: 10
+    },
+    y: {
+        x: {
+            x: 10
+        },
+        y: 0
+    }
+}
+
+for (var z in x) {
+    // Check if x[z].x is not an empty object
+    if (Object.keys(x[z].x).length !== 0) {
+        console.log('object: ', z)
+    }
+}

tests/scripts/comp.js

@@ -2,6 +2,8 @@ let susceptible2 = new Idiom("S-(B*S*I/p)");
 let infected2 = new Idiom("I+(B*S*I/p)-(u*I)");
 let recovered2 = new Idiom("R+(u*I)");
 
+infected2.addSub('asymptomatic', 10)
+
 let S = new Susceptible(["I*0.4/N"], [], true);
 let I = new Infected([0.2], [['S', 'I*0.4/N']], true);
 let R = new Recovered([], [['I', 0.4]], true);