qmk-rgb/cmd/qmk-rgb-tool/effect_list_test.go

package main

import (
	"bytes"
	"encoding/json"
	"testing"
)

// Every other JSON command emits an object, so a consumer can add fields
// later without breaking. `effect --list` returned a bare array because the
// EffectList wrapper it built was bypassed in favour of its slice.
func TestEffectListEmitsAnObjectNotABareArray(t *testing.T) {
	var out, errOut bytes.Buffer
	cmd := NewEffectCmd()
	cmd.SetOut(&out)
	cmd.SetErr(&errOut)
	cmd.SetArgs([]string{"--list"})

	if err := cmd.Execute(); err != nil {
		t.Fatalf("effect --list returned error: %v", err)
	}

	var parsed map[string][]struct {
		Zone   string `json:"zone"`
		Effect string `json:"effect"`
		ID     int    `json:"id"`
	}
	if err := json.Unmarshal(out.Bytes(), &parsed); err != nil {
		t.Fatalf("effect --list output is not a JSON object: %v (output %q)", err, out.String()[:min(80, out.Len())])
	}

	zones, ok := parsed["zones"]
	if !ok {
		t.Fatalf("output = %q, want a top-level \"zones\" key", out.String()[:min(80, out.Len())])
	}
	if len(zones) == 0 {
		t.Fatal("zones is empty, want the full catalog")
	}

	// The catalog itself must not have changed shape.
	if zones[0].Zone == "" || zones[0].Effect == "" {
		t.Errorf("zones[0] = %+v, want zone, effect and id populated", zones[0])
	}
}

func min(a, b int) int {
	if a < b {
		return a
	}
	return b
}