enforce lint in CI

Signed-off-by: Aravindhan Ayyanathan <aravindhan.a@est.tech>

Author: aravindtga

go/Makefile

@@ -25,7 +25,7 @@ lint: install-golangci-lint lint-modules
 lint-modules: $(MODULES)
 	@for f in $(^D); do \
 	(cd $$f; echo "Checking golangci-lint $$f"; \
-	$(GOBIN)/golangci-lint run ./...); \
+	$(GOBIN)/golangci-lint run ./...) || exit 1; \
 	done
 
 .PHONY: test

go/fn/internal/docs/render.go

@@ -1,4 +1,4 @@
-// Copyright 2025 The kpt Authors
+// Copyright 2025-2026 The kpt Authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -42,26 +42,26 @@ type DocOutput struct {
 // "no documentation available" message.
 func RenderHelp(w io.Writer, sections Sections, meta Metadata) {
 	if sections.Short == "" && sections.Long == "" && sections.Examples == "" && isMetadataEmpty(meta) {
-		fmt.Fprint(w, "No documentation available. Pass fn.WithDocs to fn.AsMain to enable --help.\n")
+		_, _ = fmt.Fprint(w, "No documentation available. Pass fn.WithDocs to fn.AsMain to enable --help.\n")
 		return
 	}
 
 	if sections.Short != "" {
-		fmt.Fprintf(w, "%s\n", sections.Short)
+		_, _ = fmt.Fprintf(w, "%s\n", sections.Short)
 	}
 
 	if sections.Long != "" {
 		if sections.Short != "" {
-			fmt.Fprint(w, "\n")
+			_, _ = fmt.Fprint(w, "\n")
 		}
-		fmt.Fprintf(w, "%s\n", sections.Long)
+		_, _ = fmt.Fprintf(w, "%s\n", sections.Long)
 	}
 
 	if sections.Examples != "" {
 		if sections.Short != "" || sections.Long != "" {
-			fmt.Fprint(w, "\n")
+			_, _ = fmt.Fprint(w, "\n")
 		}
-		fmt.Fprintf(w, "Examples:\n%s\n", sections.Examples)
+		_, _ = fmt.Fprintf(w, "Examples:\n%s\n", sections.Examples)
 	}
 }
 

go/fn/run.go

@@ -18,6 +18,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"path/filepath"
 	"slices"
 	"strings"
 
@@ -141,7 +142,7 @@ func AsMain(input any, opts ...Option) error {
 // handleHelp renders help text to STDOUT based on registered docs.
 func handleHelp(cfg *mainConfig) error {
 	if cfg.readme == nil && cfg.metadata == nil {
-		fmt.Fprint(os.Stdout, "No documentation available. Pass fn.WithDocs to fn.AsMain to enable --help.\n")
+		_, _ = fmt.Fprint(os.Stdout, "No documentation available. Pass fn.WithDocs to fn.AsMain to enable --help.\n")
 		return nil
 	}
 
@@ -159,7 +160,7 @@ func handleHelp(cfg *mainConfig) error {
 // handleDoc renders JSON documentation to STDOUT based on registered docs.
 func handleDoc(cfg *mainConfig) error {
 	if cfg.readme == nil && cfg.metadata == nil {
-		fmt.Fprint(os.Stdout, "{}")
+		_, _ = fmt.Fprint(os.Stdout, "{}")
 		return nil
 	}
 
@@ -183,7 +184,7 @@ func readFilesAsResourceList(paths []string) (*ResourceList, error) {
 		FunctionConfig: NewEmptyKubeObject(),
 	}
 	for _, path := range paths {
-		data, err := os.ReadFile(path)
+		data, err := os.ReadFile(filepath.Clean(path))
 		if err != nil {
 			if os.IsNotExist(err) {
 				return nil, fmt.Errorf("file not found: %s", path)

go/fn/run_filemode_property_test.go

@@ -38,7 +38,7 @@ func genKRMResource() *rapid.Generator[string] {
 		for i := range numEntries {
 			key := rapid.StringMatching(`[a-z][a-z0-9]{1,8}`).Draw(t, fmt.Sprintf("key%d", i))
 			value := rapid.StringMatching(`[a-zA-Z0-9]{1,15}`).Draw(t, fmt.Sprintf("value%d", i))
-			dataLines.WriteString(fmt.Sprintf("  %s: %s\n", key, value))
+			fmt.Fprintf(&dataLines, "  %s: %s\n", key, value)
 		}
 		return fmt.Sprintf(`apiVersion: v1
 kind: ConfigMap
@@ -65,7 +65,7 @@ func TestProperty6_FileModeEquivalence(t *testing.T) {
 		if err != nil {
 			t.Fatalf("failed to create temp dir: %v", err)
 		}
-		defer os.RemoveAll(tmpDir)
+		defer func() { _ = os.RemoveAll(tmpDir) }()
 
 		var filePaths []string
 		for i, res := range resources {

go/fn/run_flags_test.go

@@ -44,13 +44,13 @@ func captureStdout(t *testing.T, fn func()) string {
 
 	fn()
 
-	w.Close()
+	_ = w.Close()
 	os.Stdout = origStdout
 
 	var buf bytes.Buffer
 	_, err = io.Copy(&buf, r)
 	require.NoError(t, err)
-	r.Close()
+	_ = r.Close()
 
 	return buf.String()
 }
@@ -66,13 +66,13 @@ func captureStderr(t *testing.T, fn func()) string {
 
 	fn()
 
-	w.Close()
+	_ = w.Close()
 	os.Stderr = origStderr
 
 	var buf bytes.Buffer
 	_, err = io.Copy(&buf, r)
 	require.NoError(t, err)
-	r.Close()
+	_ = r.Close()
 
 	return buf.String()
 }
@@ -96,11 +96,11 @@ func TestAsMain_HelpFlag_ExitsZero(t *testing.T) {
 	origStdin := os.Stdin
 	r, w, err := os.Pipe()
 	require.NoError(t, err)
-	w.Close() // Close write end immediately — reading would get EOF
+	_ = w.Close() // Close write end immediately — reading would get EOF
 	os.Stdin = r
 	t.Cleanup(func() {
 		os.Stdin = origStdin
-		r.Close()
+		_ = r.Close()
 	})
 
 	output := captureStdout(t, func() {