fathom/internal/config/config_test.go

package config

import (
	"os"
	"path/filepath"
	"strings"
	"testing"
	"time"
)

func writeConfig(t *testing.T, body string) string {
	t.Helper()
	p := filepath.Join(t.TempDir(), "fathom.ini")
	if err := os.WriteFile(p, []byte(body), 0o644); err != nil {
		t.Fatal(err)
	}
	return p
}

func TestDefaults(t *testing.T) {
	c, err := Load("")
	if err != nil {
		t.Fatal(err)
	}
	if c.Server.Addr != ":3000" {
		t.Errorf("default addr = %q, want :3000", c.Server.Addr)
	}
	if c.Storage.Dir != "./data" {
		t.Errorf("default dir = %q", c.Storage.Dir)
	}
	// Identity attributes must default to dropped: a default that leaks the
	// operator's email into every shard is the wrong way round.
	if c.Privacy.KeepIdentityAttrs {
		t.Error("KeepIdentityAttrs defaults to true; it must default to false")
	}
}

func TestMissingFileIsNotAnError(t *testing.T) {
	// A single-binary deployment must run with no config at all.
	c, err := Load(filepath.Join(t.TempDir(), "nope.ini"))
	if err != nil {
		t.Fatalf("a missing config file should fall back to defaults: %v", err)
	}
	if c.Server.Addr != ":3000" {
		t.Errorf("addr = %q", c.Server.Addr)
	}
}

func TestParseFile(t *testing.T) {
	p := writeConfig(t, `
# a comment
; another comment

[server]
addr = :8080

[storage]
dir = /srv/fathom
flush_rows = 500
flush_interval = 2s
retention_days = 14
max_bytes = 10GB

[privacy]
keep_identity_attrs = yes
max_blob_bytes = 256KB
`)
	c, err := Load(p)
	if err != nil {
		t.Fatal(err)
	}
	if c.Server.Addr != ":8080" {
		t.Errorf("addr = %q", c.Server.Addr)
	}
	if c.Storage.Dir != "/srv/fathom" {
		t.Errorf("dir = %q", c.Storage.Dir)
	}
	if c.Storage.FlushRows != 500 {
		t.Errorf("flush_rows = %d", c.Storage.FlushRows)
	}
	if c.Storage.FlushInterval != 2*time.Second {
		t.Errorf("flush_interval = %v", c.Storage.FlushInterval)
	}
	if c.Storage.RetentionDays != 14 {
		t.Errorf("retention_days = %d", c.Storage.RetentionDays)
	}
	if c.Storage.MaxBytes != 10<<30 {
		t.Errorf("max_bytes = %d, want %d", c.Storage.MaxBytes, int64(10)<<30)
	}
	if !c.Privacy.KeepIdentityAttrs {
		t.Error("keep_identity_attrs = yes was not applied")
	}
	if c.Privacy.MaxBlobBytes != 256<<10 {
		t.Errorf("max_blob_bytes = %d", c.Privacy.MaxBlobBytes)
	}
}

// TestUnknownKeyIsReported is the behaviour a silent config parser gets wrong.
// A typo that is ignored means the setting you thought you changed never took
// effect, and nothing says so.
func TestUnknownKeyIsReported(t *testing.T) {
	p := writeConfig(t, "[storage]\nretention_dayz = 7\n")
	_, err := Load(p)
	if err == nil {
		t.Fatal("a misspelled key was accepted silently")
	}
	if !strings.Contains(err.Error(), "retention_dayz") {
		t.Errorf("error %q should name the offending key", err)
	}
}

func TestMalformedLineIsReported(t *testing.T) {
	p := writeConfig(t, "[server]\nthis is not a setting\n")
	_, err := Load(p)
	if err == nil {
		t.Fatal("a malformed line was accepted")
	}
	if !strings.Contains(err.Error(), ":2") {
		t.Errorf("error %q should carry the line number", err)
	}
}

func TestEnvOverridesFile(t *testing.T) {
	p := writeConfig(t, "[server]\naddr = :8080\n[storage]\ndir = /from/file\n")
	t.Setenv("FATHOM_ADDR", ":9999")
	t.Setenv("FATHOM_DATA_DIR", "/from/env")

	c, err := Load(p)
	if err != nil {
		t.Fatal(err)
	}
	if c.Server.Addr != ":9999" {
		t.Errorf("addr = %q, want the environment to win", c.Server.Addr)
	}
	if c.Storage.Dir != "/from/env" {
		t.Errorf("dir = %q, want the environment to win", c.Storage.Dir)
	}
}

func TestParseBytes(t *testing.T) {
	cases := map[string]int64{
		"1024": 1024, "1KB": 1 << 10, "1k": 1 << 10,
		"5MB": 5 << 20, "2GB": 2 << 30, "1TB": 1 << 40,
		"512B": 512, "1.5GB": int64(1.5 * float64(int64(1)<<30)),
	}
	for in, want := range cases {
		got, err := parseBytes(in)
		if err != nil {
			t.Errorf("parseBytes(%q): %v", in, err)
			continue
		}
		if got != want {
			t.Errorf("parseBytes(%q) = %d, want %d", in, got, want)
		}
	}
	if _, err := parseBytes("banana"); err == nil {
		t.Error("parseBytes accepted a non-number")
	}
}

func TestQuotedValues(t *testing.T) {
	p := writeConfig(t, `[storage]
dir = "/path/with spaces"
`)
	c, err := Load(p)
	if err != nil {
		t.Fatal(err)
	}
	if c.Storage.Dir != "/path/with spaces" {
		t.Errorf("dir = %q, quotes should be stripped", c.Storage.Dir)
	}
}