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) {
	t.Cleanup(vendoredDefinitions(t))
	withJSON(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 struct {
		Catalog string `json:"catalog"`
		Zones   []struct {
			Zone      string `json:"zone"`
			Channel   int    `json:"channel"`
			Subsystem string `json:"subsystem"`
			Effect    string `json:"effect"`
			ID        int    `json:"id"`
		} `json:"zones"`
	}
	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())])
	}
	if parsed.Catalog != "impact80" {
		// The catalog is named by the definition file it was read from, so the name
		// here is the vendor's own rather than a label the tool invented.
		if parsed.Catalog != "Impact 80" {
			t.Errorf("catalog = %q, want the definition file's name %q", parsed.Catalog, "Impact 80")
		}
	}

	zones := parsed.Zones
	if len(zones) == 0 {
		t.Fatal("zones is empty, want the full catalog")
	}
	if len(zones) == 0 {
		t.Fatal("zones is empty, want the full catalog")
	}

	// The catalog itself must not have lost a field, and gained the channel
	// identity a consumer needs to address the entry it finds.
	if zones[0].Zone == "" || zones[0].Effect == "" {
		t.Errorf("zones[0] = %+v, want zone, effect and id populated", zones[0])
	}
	if zones[0].Channel == 0 || zones[0].Subsystem == "" {
		t.Errorf("zones[0] = %+v, want channel and subsystem populated", zones[0])
	}
}

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