Issue-7: json: cannot unmarshal number (#8)

## Issue:
* #7

## Changes
* Replace int with float64
* Replace sweat drop emoji with droplet emoji
* Update screenshot
* Move fetch/unmarshal to dedicated function
* Add tests for Unmarshal API payloads

## TODO
- [x] Add test cases for different payloads

airgradient.go

@@ -1,40 +1,40 @@
 package main
 
 import (
+	"encoding/json"
+	"errors"
 	"io"
 	"net/http"
 	"time"
 )
 
-const AIR_GRADIENT_API_URL = "https://api.airgradient.com/public/api/v1/locations/measures/current"
-
 type AirGradientMeasures []struct {
 	LocationID         int       `json:"locationId"`
 	LocationName       string    `json:"locationName"`
-	Pm01               any       `json:"pm01"`
-	Pm02               int       `json:"pm02"`
-	Pm10               any       `json:"pm10"`
-	Pm003Count         any       `json:"pm003Count"`
+	Pm01               float64   `json:"pm01"`
+	Pm02               float64   `json:"pm02"`
+	Pm10               float64   `json:"pm10"`
+	Pm003Count         float64   `json:"pm003Count"`
 	Atmp               float64   `json:"atmp"`
-	Rhum               int       `json:"rhum"`
-	Rco2               int       `json:"rco2"`
+	Rhum               float64   `json:"rhum"`
+	Rco2               float64   `json:"rco2"`
 	Tvoc               float64   `json:"tvoc"`
-	Wifi               int       `json:"wifi"`
+	Wifi               float64   `json:"wifi"`
 	Timestamp          time.Time `json:"timestamp"`
 	LedMode            string    `json:"ledMode"`
-	LedCo2Threshold1   int       `json:"ledCo2Threshold1"`
-	LedCo2Threshold2   int       `json:"ledCo2Threshold2"`
-	LedCo2ThresholdEnd int       `json:"ledCo2ThresholdEnd"`
+	LedCo2Threshold1   float64   `json:"ledCo2Threshold1"`
+	LedCo2Threshold2   float64   `json:"ledCo2Threshold2"`
+	LedCo2ThresholdEnd float64   `json:"ledCo2ThresholdEnd"`
 	Serialno           string    `json:"serialno"`
-	FirmwareVersion    any       `json:"firmwareVersion"`
-	TvocIndex          int       `json:"tvocIndex"`
-	NoxIndex           int       `json:"noxIndex"`
+	FirmwareVersion    string    `json:"firmwareVersion"`
+	TvocIndex          float64   `json:"tvocIndex"`
+	NoxIndex           float64   `json:"noxIndex"`
 }
 
-func fetchMeasures(token string) ([]byte, error) {
+func fetchMeasures(airGradientAPIUrl string, token string) ([]byte, error) {
 	client := &http.Client{}
 
-	req, err := http.NewRequest("GET", AIR_GRADIENT_API_URL, nil)
+	req, err := http.NewRequest("GET", airGradientAPIUrl, nil)
 	if err != nil {
 		logger.Error("Creating HTTP request", "error", err)
 		return nil, err
@@ -59,3 +59,19 @@ func fetchMeasures(token string) ([]byte, error) {
 
 	return body, nil
 }
+
+func getAirGradientMeasures(airGradientAPIUrl string, token string) (AirGradientMeasures, error) {
+	payload, err := fetchMeasures(airGradientAPIUrl, token)
+	if err != nil {
+		return nil, err
+	}
+
+	var airGradientMeasures AirGradientMeasures
+
+	err = json.Unmarshal(payload, &airGradientMeasures)
+	if err != nil {
+		return nil, errors.New("Error unmarshalling JSON")
+	}
+
+	return airGradientMeasures, nil
+}

airgradient_test.go

@@ -0,0 +1,46 @@
+package main
+
+import (
+	"errors"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestGetAirGradientMeasures(t *testing.T) {
+	var testCases = []struct {
+		name        string
+		payloadFile string
+		err         error
+	}{
+		{
+			"correct-response",
+			"testdata/correct_response1.json",
+			nil,
+		},
+		{
+			"correct-response2",
+			"testdata/correct_response2.json",
+			nil,
+		},
+		{
+			"incorrect-response",
+			"testdata/incorrect_response1.json",
+			errors.New("Error unmarshalling JSON"),
+		},
+	}
+
+	for _, tC := range testCases {
+		t.Run(tC.name, func(t *testing.T) {
+			server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				http.ServeFile(w, r, tC.payloadFile)
+			}))
+			defer server.Close()
+
+			_, err := getAirGradientMeasures(server.URL, "SECRET-TOKEN")
+			assert.Equal(t, tC.err, err)
+		})
+	}
+}

main.go

@@ -1,7 +1,6 @@
 package main
 
 import (
-	"encoding/json"
 	"fmt"
 	"os"
 	"time"
@@ -12,6 +11,8 @@ import (
 	"github.com/progrium/macdriver/objc"
 )
 
+const AIR_GRADIENT_API_URL = "https://api.airgradient.com/public/api/v1/locations/measures/current"
+
 func main() {
 	macos.RunApp(launched)
 }
@@ -45,18 +46,13 @@ func launched(app appkit.Application, delegate *appkit.ApplicationDelegate) {
 		for {
 			select {
 			case <-time.After(time.Duration(cfg.Interval) * time.Second):
-				payload, err := fetchMeasures(cfg.Token)
+				airGradientMeasures, err = getAirGradientMeasures(AIR_GRADIENT_API_URL, cfg.Token)
 				if err != nil {
 					logger.Error("Fetching measures", "error", err)
-					return
-				}
-
-				err = json.Unmarshal(payload, &airGradientMeasures)
-				if err != nil {
-					logger.Error("Parsing JSON payload", "error", err)
-					return
+					continue
 				}
 			}
+
 			if len(airGradientMeasures) == 0 {
 				logger.Error("No measurements found")
 				return
@@ -71,7 +67,7 @@ func launched(app appkit.Application, delegate *appkit.ApplicationDelegate) {
 
 			// updates to the ui should happen on the main thread to avoid segfaults
 			dispatch.MainQueue().DispatchAsync(func() {
-				item.Button().SetTitle(fmt.Sprintf("🌡️ %.2f  💨 %d  💦 %d  🫧 %d",
+				item.Button().SetTitle(fmt.Sprintf("🌡️ %.2f  💨 %.0f  💧 %.1f  🫧 %.0f",
 					temperature,
 					airGradientMeasures[0].Pm02,
 					airGradientMeasures[0].Rhum,

testdata/correct_response1.json

@@ -0,0 +1 @@
+[{"locationId":12345,"locationName":"Test Loc","pm01":null,"pm02":4,"pm10":null,"pm003Count":null,"atmp":24.3,"rhum":52,"rco2":548,"tvoc":93.979355,"wifi":-58,"timestamp":"2023-10-10T03:42:11.000Z","ledMode":"co2","ledCo2Threshold1":1000,"ledCo2Threshold2":2000,"ledCo2ThresholdEnd":4000,"serialno":"aabb12","firmwareVersion":null,"tvocIndex":100,"noxIndex":1}]

testdata/correct_response2.json

@@ -0,0 +1 @@
+[{"locationId":12345,"locationName":"Test Loc","pm01":null,"pm02":4,"pm10":null,"pm003Count":null,"atmp":24.3,"rhum":53.5,"rco2":548,"tvoc":93.979355,"wifi":-58,"timestamp":"2023-10-10T03:42:11.000Z","ledMode":"co2","ledCo2Threshold1":1000,"ledCo2Threshold2":2000,"ledCo2ThresholdEnd":4000,"serialno":"aabb12","firmwareVersion":null,"tvocIndex":100,"noxIndex":1}]

testdata/incorrect_response1.json

@@ -0,0 +1,10 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+<meta charset="utf-8">
+<title>Error</title>
+</head>
+<body>
+<pre>Cannot GET /public/api/v1/locations/measures/current1</pre>
+</body>
+</html>