Added unit tests

.github/workflows/tests.yml

@@ -0,0 +1,19 @@
+name: Tests
+on:
+  push:
+    branches:
+      - main
+  workflow_dispatch:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    
+    steps:
+      - uses: actions/checkout@v4
+      - name: Setup Go stable
+        uses: actions/setup-go@v5
+        with:
+          go-version: 'stable'
+      - name: "Running unit tests"
+        run:  go test ./... -v

Dockerfile

@@ -8,6 +8,9 @@ WORKDIR /app
 # Copy source files
 COPY . .
 
+# Run unit tests
+RUN go test ./... -v
+
 # Build the application
 RUN go build -ldflags="-s -w" -o zephyr
 

README.md

@@ -4,6 +4,7 @@
 <h6><i>real-time weather forecast service</i></h6>
 
 [![](https://github.com/ceticamarco/zephyr/actions/workflows/docker.yml/badge.svg)](https://github.com/ceticamarco/zephyr/actions/workflows/docker.yml)
+[![](https://github.com/ceticamarco/zephyr/actions/workflows/tests.yml/badge.svg)](https://github.com/ceticamarco/zephyr/actions/workflows/tests.yml)
 
 </div>
 
@@ -163,7 +164,7 @@ will yield
 }
 ```
 
-> [!INFO]
+> [!NOTE]
 > To convert OpenWeatherMap's moon phase value to the illumination percentage, 
 > I've used the following formula:
 > 
@@ -333,5 +334,12 @@ This will build the container image and start the service in detached mode. By d
 the service will be available at `http://127.0.0.1:3000`, but you can easily change this property
 but editing the `compose.yml` as stated above.
 
+## Unit tests
+You can run the unit tests by issuing the following command:
+
+```sh
+ go test ./... -v
+ ```
+
 ## License
 This software is released under the GPLv3 license. You can find a copy of the license with this repository or by visiting the [following page](https://choosealicense.com/licenses/gpl-3.0/).

model/windModel_test.go

@@ -0,0 +1,28 @@
+package model
+
+import (
+	"testing"
+)
+
+type TestEntry struct {
+	Name     string
+	Input    float64
+	Expected string
+}
+
+func TestGetCardinalDir(t *testing.T) {
+	tests := []TestEntry{
+		{"Bounded value", 65.4, "ENE"},
+		{"Out of bound value", 450.3, "E"},
+	}
+
+	for _, test := range tests {
+		t.Run(test.Name, func(t *testing.T) {
+			got, _ := GetCardinalDir(test.Input)
+
+			if got != test.Expected {
+				t.Errorf("Got %s, wanted %s", got, test.Expected)
+			}
+		})
+	}
+}

statistics/primitives_test.go

@@ -0,0 +1,123 @@
+package statistics
+
+import (
+	"math"
+	"testing"
+)
+
+type TestEntry struct {
+	Name     string
+	Input    []float64
+	Expected float64
+}
+
+func cmpVal(x, y float64) bool {
+	const epsilon = 1e-9
+
+	return math.Abs(x-y) < epsilon
+}
+
+func TestMean(t *testing.T) {
+	tests := []TestEntry{
+		{"Empty list", []float64{}, 0},
+		{"Single element", []float64{5.0}, 5.0},
+		{"Multiple elements", []float64{2.3, 6.4, -2.2, 8.4}, 3.725},
+	}
+
+	for _, test := range tests {
+		t.Run(test.Name, func(t *testing.T) {
+			got := Mean(test.Input)
+			if !cmpVal(got, test.Expected) {
+				t.Errorf("Got %v, wanted %v", got, test.Expected)
+			}
+		})
+	}
+}
+
+func TestStdDev(t *testing.T) {
+	tests := []TestEntry{
+		{"Empty list", []float64{}, 0},
+		{"Single element", []float64{5.0}, 0},
+		{"Multiple elements", []float64{5.0, -4.2, 3.4, 7.2}, 4.288064831599448},
+	}
+
+	for _, test := range tests {
+		t.Run(test.Name, func(t *testing.T) {
+			got := StdDev(test.Input)
+			if !cmpVal(got, test.Expected) {
+				t.Errorf("Got %v, wanted %v", got, test.Expected)
+			}
+		})
+	}
+}
+
+func TestMedian(t *testing.T) {
+	tests := []TestEntry{
+		{"Empty list", []float64{}, 0},
+		{"Single element", []float64{5.0}, 5.0},
+		{"Multiple elements (even)", []float64{5.0, -4.2, 3.4, 7.2}, 4.2},
+		{"Multiple elements (odd)", []float64{5.0, -4.2, 1.4, 3.4, 7.2}, 3.4},
+	}
+
+	for _, test := range tests {
+		t.Run(test.Name, func(t *testing.T) {
+			got := Median(test.Input)
+			if !cmpVal(got, test.Expected) {
+				t.Errorf("Got %v, wanted %v", got, test.Expected)
+			}
+		})
+	}
+}
+
+func TestMode(t *testing.T) {
+	tests := []TestEntry{
+		{"Empty list", []float64{}, 0},
+		{"Single element", []float64{5.0}, 5.0},
+		{"Unique modes", []float64{1.0, 2.0, 2.0, 3.0}, 2.0},
+		{"Multi-modal", []float64{1.0, 1.0, 2.0, 3.0, 3.0}, 3.0},
+	}
+
+	for _, test := range tests {
+		t.Run(test.Name, func(t *testing.T) {
+			got := Mode(test.Input)
+			if !cmpVal(got, test.Expected) {
+				t.Errorf("Got %v, wanted %v", got, test.Expected)
+			}
+		})
+	}
+}
+
+func TestRobustZScore(t *testing.T) {
+	// Gaussian distributed dataset representing "normal"
+	// temperatures; that is, without anomalies
+	normalTemps := []float64{
+		18.0, 19.0, 19.0, 20.0, 20.0,
+		20.0, 21.0, 21.0, 21.0, 21.0,
+		22.0, 22.0, 22.0, 22.0, 22.0,
+		23.0, 23.0, 23.0, 24.0, 24.0,
+	}
+
+	tests := []TestEntry{
+		{"Empty list", []float64{}, 0},
+		{"Single element", []float64{20.0}, 0},
+		{"Temperatures without anomalies", normalTemps, 0},
+		{"High anomaly", append(normalTemps, 30.0), 30.0},
+		{"Low anomaly", append(normalTemps, 5.0), 5.0},
+	}
+
+	for _, test := range tests {
+		t.Run(test.Name, func(t *testing.T) {
+			got := RobustZScore(test.Input)
+
+			if len(got) != 0 {
+				if !cmpVal(got[0].Value, test.Expected) {
+					t.Errorf("Got %v, wanted %v", got, test.Expected)
+				}
+			} else {
+				if test.Expected != 0 {
+					t.Errorf("Got [], wanted %v", test.Expected)
+				}
+			}
+		})
+	}
+}