chore(lint): add golangci-lint config and fix the 71 findings it surfaces

.github/workflows/ci.yml

@@ -17,7 +17,7 @@ jobs:
       - name: Setup Go
         uses: actions/setup-go@v5
         with:
-          go-version: '1.23'
+          go-version: '1.24'
 
       - name: Download dependencies
         run: go mod download
@@ -44,9 +44,11 @@ jobs:
       - name: Setup Go
         uses: actions/setup-go@v5
         with:
-          go-version: '1.23'
+          go-version: '1.24'
 
       - name: Run golangci-lint
-        uses: golangci/golangci-lint-action@v6
+        # v8+ is required: .golangci.yml uses the golangci-lint v2 config schema
+        # (version: "2", linters.settings, formatters), which v1 cannot parse.
+        uses: golangci/golangci-lint-action@v8
         with:
-          version: latest
+          version: v2.12.2

.golangci.yml

@@ -0,0 +1,67 @@
+version: "2"
+
+run:
+  timeout: 8m
+
+linters:
+  default: standard
+  enable:
+    # standard set (errcheck, govet, ineffassign, staticcheck, unused) plus:
+    - errorlint    # error comparisons/assertions that break under wrapping
+    - nilerr       # returning nil when a non-nil error is in hand
+    - gocritic     # opinionated but high-signal style/perf diagnostics
+    - revive       # doc comments, shadowed builtins, unused params
+    - unconvert    # redundant type conversions
+    - misspell     # typos in comments and strings
+    - bodyclose    # unclosed HTTP response bodies
+
+  settings:
+    revive:
+      rules:
+        - name: blank-imports
+        - name: context-as-argument
+        - name: context-keys-type
+        - name: dot-imports
+        - name: error-return
+        - name: error-strings
+        - name: error-naming
+        - name: exported
+        - name: increment-decrement
+        - name: var-naming
+        - name: package-comments
+        - name: range
+        - name: receiver-naming
+        - name: time-naming
+        - name: indent-error-flow
+        - name: errorf
+        - name: redefines-builtin-id
+        - name: unused-parameter
+        - name: unreachable-code
+        - name: superfluous-else
+
+  exclusions:
+    rules:
+      # Mock and fake implementations must match interface signatures, so their
+      # parameters are structurally required even when unused. Renaming them all
+      # to `_` would make the test doubles harder to read, not easier.
+      - path: _test\.go
+        linters:
+          - revive
+        text: "unused-parameter"
+
+      # stats.StatsResult, budget.BudgetEstimate and budget.BudgetSource trip
+      # revive's stutter check. Renaming an exported type is a cross-package API
+      # break (15 call sites across the repo) and does not belong in a lint-only
+      # change; each should be done deliberately in its own commit.
+      - path: (internal/stats/|internal/budget/)
+        linters:
+          - revive
+        text: "and that stutters"
+
+formatters:
+  enable:
+    - gofmt
+
+issues:
+  max-issues-per-linter: 0
+  max-same-issues: 0

cmd/nightshift/commands/budget.go

@@ -21,7 +21,7 @@ var budgetCmd = &cobra.Command{
 	Long: `Display current budget status and usage.
 
 Shows spending across all providers or a specific provider.`,
-	RunE: func(cmd *cobra.Command, args []string) error {
+	RunE: func(cmd *cobra.Command, _ []string) error {
 		provider, _ := cmd.Flags().GetString("provider")
 		return runBudget(provider)
 	},

cmd/nightshift/commands/config.go

@@ -21,7 +21,7 @@ var configCmd = &cobra.Command{
 
 Shows current configuration merged from global and project configs.
 Use subcommands to get/set specific values or validate the config.`,
-	RunE: func(cmd *cobra.Command, args []string) error {
+	RunE: func(_ *cobra.Command, _ []string) error {
 		return runConfigShow()
 	},
 }
@@ -36,7 +36,7 @@ Examples:
   nightshift config get providers.claude.enabled
   nightshift config get logging.level`,
 	Args: cobra.ExactArgs(1),
-	RunE: func(cmd *cobra.Command, args []string) error {
+	RunE: func(_ *cobra.Command, args []string) error {
 		return runConfigGet(args[0])
 	},
 }
@@ -66,7 +66,7 @@ var configValidateCmd = &cobra.Command{
 	Long: `Validate the current configuration.
 
 Checks both global and project configs for errors.`,
-	RunE: func(cmd *cobra.Command, args []string) error {
+	RunE: func(_ *cobra.Command, _ []string) error {
 		return runConfigValidate()
 	},
 }

cmd/nightshift/commands/daemon.go

@@ -2,6 +2,7 @@ package commands
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"os"
 	"os/exec"
@@ -129,7 +130,7 @@ func isDaemonRunning() (bool, int) {
 	return isProcessRunning(pid), pid
 }
 
-func runDaemonStart(cmd *cobra.Command, args []string) error {
+func runDaemonStart(_ *cobra.Command, _ []string) error {
 	// Check if already running
 	if running, pid := isDaemonRunning(); running {
 		return fmt.Errorf("daemon already running (pid %d)", pid)
@@ -238,7 +239,7 @@ func runDaemonLoop(cfg *config.Config) error {
 	<-ctx.Done()
 
 	// Stop scheduler gracefully
-	if err := sched.Stop(); err != nil && err != scheduler.ErrNotRunning {
+	if err := sched.Stop(); err != nil && !errors.Is(err, scheduler.ErrNotRunning) {
 		log.Errorf("stopping scheduler: %v", err)
 	}
 
@@ -564,28 +565,30 @@ func takeSnapshot(ctx context.Context, cfg *config.Config, database *db.DB, log
 
 	if cfg.Providers.Claude.Enabled {
 		snapshot, err := collector.TakeSnapshot(ctx, "claude")
-		if err != nil {
+		switch {
+		case err != nil:
 			log.Warnf("snapshot claude: %v", err)
-		} else if snapshot.ScrapedPct != nil {
+		case snapshot.ScrapedPct != nil:
 			log.Infof("snapshot claude: %.1f%%", *snapshot.ScrapedPct)
-		} else {
+		default:
 			log.Info("snapshot claude: local-only")
 		}
 	}
 
 	if cfg.Providers.Codex.Enabled {
 		snapshot, err := collector.TakeSnapshot(ctx, "codex")
-		if err != nil {
+		switch {
+		case err != nil:
 			log.Warnf("snapshot codex: %v", err)
-		} else if snapshot.ScrapedPct != nil {
+		case snapshot.ScrapedPct != nil:
 			log.Infof("snapshot codex: %.1f%%", *snapshot.ScrapedPct)
-		} else {
+		default:
 			log.Info("snapshot codex: local-only")
 		}
 	}
 }
 
-func pruneSnapshots(ctx context.Context, cfg *config.Config, database *db.DB, log *logging.Logger) {
+func pruneSnapshots(_ context.Context, cfg *config.Config, database *db.DB, log *logging.Logger) {
 	collector := snapshots.NewCollector(database, nil, nil, nil, nil, weekStartDayFromConfig(cfg))
 	deleted, err := collector.Prune(cfg.Budget.SnapshotRetentionDays)
 	if err != nil {
@@ -609,7 +612,7 @@ func weekStartDayFromConfig(cfg *config.Config) time.Weekday {
 	}
 }
 
-func runDaemonStop(cmd *cobra.Command, args []string) error {
+func runDaemonStop(_ *cobra.Command, _ []string) error {
 	running, pid := isDaemonRunning()
 	if !running {
 		// Check if PID file exists but process is dead
@@ -657,7 +660,7 @@ func runDaemonStop(cmd *cobra.Command, args []string) error {
 	}
 }
 
-func runDaemonStatus(cmd *cobra.Command, args []string) error {
+func runDaemonStatus(_ *cobra.Command, _ []string) error {
 	running, pid := isDaemonRunning()
 
 	if !running {

cmd/nightshift/commands/doctor.go

@@ -50,7 +50,7 @@ func init() {
 	rootCmd.AddCommand(doctorCmd)
 }
 
-func runDoctor(cmd *cobra.Command, args []string) error {
+func runDoctor(_ *cobra.Command, _ []string) error {
 	// Augment PATH the same way 'run' does so CLI checks are accurate.
 	ensurePATH()
 

cmd/nightshift/commands/init.go

@@ -36,7 +36,7 @@ func init() {
 	rootCmd.AddCommand(initCmd)
 }
 
-func runInit(cmd *cobra.Command, args []string) error {
+func runInit(cmd *cobra.Command, _ []string) error {
 	global, _ := cmd.Flags().GetBool("global")
 	force, _ := cmd.Flags().GetBool("force")
 

cmd/nightshift/commands/install.go

@@ -55,7 +55,7 @@ func init() {
 }
 
 // runInstall implements the install command
-func runInstall(cmd *cobra.Command, args []string) error {
+func runInstall(_ *cobra.Command, args []string) error {
 	// Determine service type
 	serviceType := ""
 	if len(args) > 0 {
@@ -378,7 +378,7 @@ func installCron(binaryPath string, cfg *config.Config) error {
 }
 
 // runUninstall implements the uninstall command
-func runUninstall(cmd *cobra.Command, args []string) error {
+func runUninstall(_ *cobra.Command, _ []string) error {
 	var errors []string
 	removed := false
 

cmd/nightshift/commands/logs.go

@@ -24,7 +24,7 @@ var logsCmd = &cobra.Command{
 	Long: `View nightshift logs.
 
 Displays recent log entries. Use --follow to stream logs in real-time.`,
-	RunE: func(cmd *cobra.Command, args []string) error {
+	RunE: func(cmd *cobra.Command, _ []string) error {
 		tail, _ := cmd.Flags().GetInt("tail")
 		follow, _ := cmd.Flags().GetBool("follow")
 		export, _ := cmd.Flags().GetString("export")

cmd/nightshift/commands/preview.go

@@ -44,7 +44,7 @@ func init() {
 	rootCmd.AddCommand(previewCmd)
 }
 
-func runPreview(cmd *cobra.Command, args []string) error {
+func runPreview(cmd *cobra.Command, _ []string) error {
 	runs, _ := cmd.Flags().GetInt("runs")
 	projectPath, _ := cmd.Flags().GetString("project")
 	taskFilter, _ := cmd.Flags().GetString("task")

cmd/nightshift/commands/preview_output.go

@@ -83,11 +83,12 @@ func renderPreviewText(result *previewResult, opts previewTextOptions) string {
 			fmt.Fprintln(b, line)
 		}
 	}
-	if result.TaskFilter != "" {
+	switch {
+	case result.TaskFilter != "":
 		fmt.Fprintf(b, "  Task filter: %s\n", result.TaskFilter)
-	} else if len(result.EnabledTasks) == 0 {
+	case len(result.EnabledTasks) == 0:
 		b.WriteString("  Task filter: all enabled tasks (none explicitly enabled)\n")
-	} else {
+	default:
 		fmt.Fprintf(b, "  Task filter: enabled list (%d) [%s]\n", len(result.EnabledTasks), strings.Join(result.EnabledTasks, ", "))
 	}
 	if opts.Explain && result.ProjectCount > 1 {
@@ -347,7 +348,7 @@ func renderDiagnosticsText(b *strings.Builder, styles previewStyles, diagnostics
 	renderCooldownsText(b, styles, diagnostics.Cooldowns, indent)
 }
 
-func renderCooldownsText(b *strings.Builder, styles previewStyles, cooldowns []previewCooldownEntry, indent string) {
+func renderCooldownsText(b *strings.Builder, _ previewStyles, cooldowns []previewCooldownEntry, indent string) {
 	if len(cooldowns) == 0 {
 		return
 	}

cmd/nightshift/commands/report.go

@@ -47,7 +47,7 @@ var reportCmd = &cobra.Command{
 	Long: `View structured reports from recent nightshift runs.
 
 By default, shows a polished overview of what happened during the last night.`,
-	RunE: func(cmd *cobra.Command, args []string) error {
+	RunE: func(cmd *cobra.Command, _ []string) error {
 		opts := reportOptions{}
 		opts.reportType, _ = cmd.Flags().GetString("report")
 		opts.period, _ = cmd.Flags().GetString("period")
@@ -895,16 +895,17 @@ func renderReportBudget(styles reportStyles, runs []reportRun) string {
 		b.WriteString(styles.Accent.Render(header))
 		b.WriteString("\n")
 
-		if summary.BudgetStart > 0 {
+		switch {
+		case summary.BudgetStart > 0:
 			fmt.Fprintf(&b, "  %s %s used / %s start (%s remaining)\n",
 				styles.Label.Render("Budget:"),
 				formatTokensCompact(summary.TokensUsed),
 				formatTokensCompact(summary.BudgetStart),
 				formatTokensCompact(summary.BudgetRemaining),
 			)
-		} else if summary.TokensUsed > 0 {
+		case summary.TokensUsed > 0:
 			fmt.Fprintf(&b, "  %s %s\n", styles.Label.Render("Tokens:"), formatTokensCompact(summary.TokensUsed))
-		} else {
+		default:
 			b.WriteString("  No budget data recorded\n")
 		}
 

cmd/nightshift/commands/run.go

@@ -117,7 +117,7 @@ func init() {
 	rootCmd.AddCommand(runCmd)
 }
 
-func runRun(cmd *cobra.Command, args []string) error {
+func runRun(cmd *cobra.Command, _ []string) error {
 	dryRun, _ := cmd.Flags().GetBool("dry-run")
 	projectPath, _ := cmd.Flags().GetString("project")
 	taskFilter, _ := cmd.Flags().GetString("task")
@@ -465,7 +465,8 @@ func buildPreflight(p executeRunParams) (*preflightPlan, error) {
 		// Select tasks
 		var selectedTasks []tasks.ScoredTask
 
-		if p.taskFilter != "" {
+		switch {
+		case p.taskFilter != "":
 			def, err := tasks.GetDefinition(tasks.TaskType(p.taskFilter))
 			if err != nil {
 				return nil, fmt.Errorf("unknown task type: %s", p.taskFilter)
@@ -475,15 +476,15 @@ func buildPreflight(p executeRunParams) (*preflightPlan, error) {
 				Score:      p.selector.ScoreTask(def.Type, projectPath),
 				Project:    projectPath,
 			}}
-		} else if p.randomTask {
+		case p.randomTask:
 			taskBudget := choice.allowance.Allowance
 			if p.ignoreBudget {
 				taskBudget = math.MaxInt64
 			}
 			if picked := p.selector.SelectRandom(taskBudget, projectPath); picked != nil {
 				selectedTasks = []tasks.ScoredTask{*picked}
 			}
-		} else {
+		default:
 			n := p.maxTasks
 			if n <= 0 {
 				n = 1

cmd/nightshift/commands/setup.go

@@ -36,7 +36,7 @@ var setupCmd = &cobra.Command{
 
 Creates/updates the global config, validates providers, runs a snapshot, previews the next run,
 and optionally installs/enables the daemon.`,
-	RunE: func(cmd *cobra.Command, args []string) error {
+	RunE: func(_ *cobra.Command, _ []string) error {
 		model, err := newSetupModel()
 		if err != nil {
 			return err
@@ -1507,11 +1507,12 @@ func renderEnvChecks(cfg *config.Config) string {
 	// Check for Copilot CLI (gh or copilot binary)
 	_, ghErr := execLookPath("gh")
 	_, copilotErr := execLookPath("copilot")
-	if ghErr != nil && copilotErr != nil {
+	switch {
+	case ghErr != nil && copilotErr != nil:
 		fmt.Fprintf(&b, "  %s %s\n", styleWarn.Render("Note:"), "Copilot CLI not found (install via 'gh' or native 'copilot')")
-	} else if ghErr == nil {
+	case ghErr == nil:
 		fmt.Fprintf(&b, "  %s %s\n", styleOk.Render("OK:"), "gh CLI available (use 'gh copilot')")
-	} else {
+	default:
 		fmt.Fprintf(&b, "  %s %s\n", styleOk.Render("OK:"), "copilot CLI available")
 	}
 	if cfg.Providers.Claude.Enabled {
@@ -1910,11 +1911,11 @@ func uninstallService(service string) error {
 
 func mustExecutablePath() string {
 	path, _ := os.Executable()
-	real, err := filepath.EvalSymlinks(path)
+	resolved, err := filepath.EvalSymlinks(path)
 	if err != nil {
 		return path
 	}
-	return real
+	return resolved
 }
 
 func writeGlobalConfig(cfg *config.Config) error {