first commit

config_test.go

@@ -0,0 +1,113 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+// Copyright (C) 2026 Bryan Joshua Pedini
+
+package main
+
+import (
+	"os"
+	"os/exec"
+	"strings"
+	"testing"
+)
+
+// TestLoadConfigDefaults exercises the success path in-process: all required
+// vars set, defaults left unset, and asserts the documented defaults.
+func TestLoadConfigDefaults(t *testing.T) {
+	t.Setenv("PDNS_API_KEY", "k")
+	t.Setenv("MYSQL_DSN", "user:pass@tcp(127.0.0.1:3306)/db")
+	t.Setenv("PUID", "1000")
+	t.Setenv("PGID", "1000")
+	os.Unsetenv("LISTEN_ADDR")
+	os.Unsetenv("TABLE_PREFIX")
+	os.Unsetenv("DEFAULT_TTL")
+	os.Unsetenv("PDNS_SERVER_ID")
+	os.Unsetenv("LOG_LEVEL")
+
+	cfg := LoadConfig()
+
+	if cfg.ListenAddr != ":3000" {
+		t.Errorf("ListenAddr = %q, want :3000", cfg.ListenAddr)
+	}
+	if cfg.TablePrefix != "coredns_" {
+		t.Errorf("TablePrefix = %q, want coredns_", cfg.TablePrefix)
+	}
+	if cfg.DefaultTTL != 120 {
+		t.Errorf("DefaultTTL = %d, want 120", cfg.DefaultTTL)
+	}
+	if cfg.PDNSServerID != "localhost" {
+		t.Errorf("PDNSServerID = %q, want localhost", cfg.PDNSServerID)
+	}
+	if cfg.LogLevel != "info" {
+		t.Errorf("LogLevel = %q, want info", cfg.LogLevel)
+	}
+}
+
+// TestLoadConfigFatal exercises the os.Exit(1) paths of LoadConfig via a
+// re-exec subprocess, since LoadConfig calls os.Exit directly and cannot be
+// asserted in-process.
+func TestLoadConfigFatal(t *testing.T) {
+	baseEnv := map[string]string{
+		"PDNS_API_KEY": "k",
+		"MYSQL_DSN":    "user:pass@tcp(127.0.0.1:3306)/db",
+		"PUID":         "1000",
+		"PGID":         "1000",
+	}
+
+	tests := []struct {
+		name      string
+		mutate    map[string]string // overrides/additions to baseEnv; "" value means unset
+		wantInErr string
+	}{
+		{"missing PDNS_API_KEY", map[string]string{"PDNS_API_KEY": ""}, "PDNS_API_KEY"},
+		{"missing MYSQL_DSN", map[string]string{"MYSQL_DSN": ""}, "MYSQL_DSN"},
+		{"missing PUID", map[string]string{"PUID": ""}, "PUID"},
+		{"missing PGID", map[string]string{"PGID": ""}, "PGID"},
+		{"PUID zero rejected", map[string]string{"PUID": "0"}, "root"},
+		{"PGID zero rejected", map[string]string{"PGID": "0"}, "root"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			env := map[string]string{}
+			for k, v := range baseEnv {
+				env[k] = v
+			}
+			for k, v := range tt.mutate {
+				env[k] = v
+			}
+
+			cmd := exec.Command(os.Args[0], "-test.run=TestConfigFatalHelper")
+			cmd.Env = []string{"GO_CONFIG_CRASH=1"}
+			for k, v := range env {
+				if v != "" {
+					cmd.Env = append(cmd.Env, k+"="+v)
+				}
+			}
+
+			out, err := cmd.CombinedOutput()
+			if err == nil {
+				t.Fatalf("expected non-zero exit, got success. output: %s", out)
+			}
+			exitErr, ok := err.(*exec.ExitError)
+			if !ok {
+				t.Fatalf("expected *exec.ExitError, got %T: %v", err, err)
+			}
+			if exitErr.ExitCode() == 0 {
+				t.Fatalf("expected non-zero exit code")
+			}
+			if !strings.Contains(string(out), tt.wantInErr) {
+				t.Fatalf("stderr output = %q, want substring %q", out, tt.wantInErr)
+			}
+		})
+	}
+}
+
+// TestConfigFatalHelper is not a real test; it's invoked as a subprocess by
+// TestLoadConfigFatal via -test.run, guarded by GO_CONFIG_CRASH so it never
+// runs (and never touches the DB) under a normal `go test` invocation.
+func TestConfigFatalHelper(t *testing.T) {
+	if os.Getenv("GO_CONFIG_CRASH") == "" {
+		t.Skip("only runs as a re-exec subprocess")
+	}
+	LoadConfig()
+}