fix(cmd): handle errors and improve output formatting

* update error handling in various commands to use blank identifier
* enhance output formatting for better readability
* add golangci-lint to Makefile for linting checks

.golangci.yml

@@ -0,0 +1,4 @@
+version: "2"
+
+linters:
+  default: standard

Makefile

@@ -20,9 +20,10 @@ vet:
 fmt:
 	go fmt ./...
 
-## lint: vet + format check
+## lint: vet + format check + golangci-lint
 lint: vet
 	test -z "$$(gofmt -l .)" || (echo "gofmt needed:"; gofmt -l .; exit 1)
+	golangci-lint run ./...
 
 ## clean: remove build artifacts
 clean:

cmd/pgtidy/config.go

@@ -11,7 +11,7 @@ import (
 func cmdConfig(args []string, stdin io.Reader, stdout, stderr io.Writer) int {
 	for _, a := range args {
 		if a == "-h" || a == "--help" {
-			fmt.Fprintln(stdout, "pgtidy config — print effective configuration resolved from .pgtidy.yaml")
+			_, _ = fmt.Fprintln(stdout, "pgtidy config — print effective configuration resolved from .pgtidy.yaml")
 			return 0
 		}
 	}
@@ -21,14 +21,14 @@ func cmdConfig(args []string, stdin io.Reader, stdout, stderr io.Writer) int {
 	}
 	st, err := config.Load(wd)
 	if err != nil {
-		fmt.Fprintf(stderr, "pgtidy: %v\n", err)
+		_, _ = fmt.Fprintf(stderr, "pgtidy: %v\n", err)
 		return 2
 	}
-	fmt.Fprintf(stdout, "indent:       %q\n", st.Indent)
-	fmt.Fprintf(stdout, "newline:      %q\n", st.Newline)
-	fmt.Fprintf(stdout, "keyword_case: %s\n", st.KeywordCase)
-	fmt.Fprintf(stdout, "ident_case:   %s\n", st.IdentCase)
-	fmt.Fprintf(stdout, "type_case:    %s\n", st.TypeCase)
-	fmt.Fprintf(stdout, "commas:       %s\n", st.Commas)
+	_, _ = fmt.Fprintf(stdout, "indent:       %q\n", st.Indent)
+	_, _ = fmt.Fprintf(stdout, "newline:      %q\n", st.Newline)
+	_, _ = fmt.Fprintf(stdout, "keyword_case: %s\n", st.KeywordCase)
+	_, _ = fmt.Fprintf(stdout, "ident_case:   %s\n", st.IdentCase)
+	_, _ = fmt.Fprintf(stdout, "type_case:    %s\n", st.TypeCase)
+	_, _ = fmt.Fprintf(stdout, "commas:       %s\n", st.Commas)
 	return 0
 }

cmd/pgtidy/fmt.go

@@ -37,7 +37,7 @@ func cmdFmt(args []string, stdin io.Reader, stdout, stderr io.Writer) int {
 			return 0
 		default:
 			if len(a) > 1 && a[0] == '-' {
-				fmt.Fprintf(stderr, "pgtidy fmt: unknown flag %q\n", a)
+				_, _ = fmt.Fprintf(stderr, "pgtidy fmt: unknown flag %q\n", a)
 				return 2
 			}
 			files = append(files, a)
@@ -51,7 +51,7 @@ func cmdFmt(args []string, stdin io.Reader, stdout, stderr io.Writer) int {
 	}
 	st, err := config.Load(wd)
 	if err != nil {
-		fmt.Fprintf(stderr, "%v\n", err)
+		_, _ = fmt.Fprintf(stderr, "%v\n", err)
 		return 2
 	}
 
@@ -59,7 +59,7 @@ func cmdFmt(args []string, stdin io.Reader, stdout, stderr io.Writer) int {
 	if len(files) == 0 {
 		src, err := io.ReadAll(stdin)
 		if err != nil {
-			fmt.Fprintf(stderr, "pgtidy: reading stdin: %v\n", err)
+			_, _ = fmt.Fprintf(stderr, "pgtidy: reading stdin: %v\n", err)
 			return 2
 		}
 		out := format.File(parser.Parse(string(src)), st)
@@ -69,9 +69,9 @@ func cmdFmt(args []string, stdin io.Reader, stdout, stderr io.Writer) int {
 				return 1
 			}
 		case diff:
-			io.WriteString(stdout, unifiedDiff(string(src), out, "stdin"))
+			_, _ = io.WriteString(stdout, unifiedDiff(string(src), out, "stdin"))
 		default:
-			io.WriteString(stdout, out)
+			_, _ = io.WriteString(stdout, out)
 		}
 		return 0
 	}
@@ -81,7 +81,7 @@ func cmdFmt(args []string, stdin io.Reader, stdout, stderr io.Writer) int {
 	for _, path := range files {
 		src, err := os.ReadFile(path)
 		if err != nil {
-			fmt.Fprintf(stderr, "pgtidy: %v\n", err)
+			_, _ = fmt.Fprintf(stderr, "pgtidy: %v\n", err)
 			exit = 2
 			continue
 		}
@@ -94,22 +94,22 @@ func cmdFmt(args []string, stdin io.Reader, stdout, stderr io.Writer) int {
 		case write:
 			if changed {
 				if err := os.WriteFile(path, []byte(out), 0o644); err != nil {
-					fmt.Fprintf(stderr, "pgtidy: writing %s: %v\n", path, err)
+					_, _ = fmt.Fprintf(stderr, "pgtidy: writing %s: %v\n", path, err)
 					exit = 2
 				}
 			}
 		case list:
 			if changed {
-				fmt.Fprintln(stdout, path)
+				_, _ = fmt.Fprintln(stdout, path)
 			}
 		case diff:
 			if changed {
-				io.WriteString(stdout, unifiedDiff(string(src), out, path))
+				_, _ = io.WriteString(stdout, unifiedDiff(string(src), out, path))
 			}
 		case check:
 			// handled after loop via anyDiff
 		default:
-			io.WriteString(stdout, out)
+			_, _ = io.WriteString(stdout, out)
 		}
 	}
 	if check && anyDiff && exit == 0 {

cmd/pgtidy/lint.go

@@ -37,7 +37,7 @@ func cmdLint(args []string, stdin io.Reader, stdout, stderr io.Writer) int {
 				}
 			}
 		case len(a) > 1 && a[0] == '-':
-			fmt.Fprintf(stderr, "pgtidy lint: unknown flag %q\n", a)
+			_, _ = fmt.Fprintf(stderr, "pgtidy lint: unknown flag %q\n", a)
 			return 2
 		default:
 			files = append(files, a)
@@ -75,7 +75,7 @@ func cmdLint(args []string, stdin io.Reader, stdout, stderr io.Writer) int {
 			if loc == "" {
 				loc = "stdin"
 			}
-			fmt.Fprintf(stdout, "%s: [%s] %s: %s\n", loc, d.RuleID, d.Severity, d.Message)
+			_, _ = fmt.Fprintf(stdout, "%s: [%s] %s: %s\n", loc, d.RuleID, d.Severity, d.Message)
 		}
 	}
 
@@ -84,18 +84,18 @@ func cmdLint(args []string, stdin io.Reader, stdout, stderr io.Writer) int {
 	if len(files) == 0 {
 		src, err := io.ReadAll(stdin)
 		if err != nil {
-			fmt.Fprintf(stderr, "pgtidy: reading stdin: %v\n", err)
+			_, _ = fmt.Fprintf(stderr, "pgtidy: reading stdin: %v\n", err)
 			return 2
 		}
 		diags, err := check(string(src), "")
 		if err != nil {
-			fmt.Fprintf(stderr, "pgtidy: %v\n", err)
+			_, _ = fmt.Fprintf(stderr, "pgtidy: %v\n", err)
 			return 2
 		}
 		if fix {
 			fixed := lint.ApplyFixes(string(src), diags)
 			if fixed != string(src) {
-				io.WriteString(stdout, fixed)
+				_, _ = io.WriteString(stdout, fixed)
 				return 0
 			}
 		}
@@ -107,25 +107,25 @@ func cmdLint(args []string, stdin io.Reader, stdout, stderr io.Writer) int {
 		for _, path := range files {
 			src, err := os.ReadFile(path)
 			if err != nil {
-				fmt.Fprintf(stderr, "pgtidy: %v\n", err)
+				_, _ = fmt.Fprintf(stderr, "pgtidy: %v\n", err)
 				return 2
 			}
 			diags, err := check(string(src), path)
 			if err != nil {
-				fmt.Fprintf(stderr, "pgtidy: %v\n", err)
+				_, _ = fmt.Fprintf(stderr, "pgtidy: %v\n", err)
 				return 2
 			}
 			if fix {
 				fixed := lint.ApplyFixes(string(src), diags)
 				if fixed != string(src) {
 					if err := os.WriteFile(path, []byte(fixed), 0o644); err != nil {
-						fmt.Fprintf(stderr, "pgtidy: writing %s: %v\n", path, err)
+						_, _ = fmt.Fprintf(stderr, "pgtidy: writing %s: %v\n", path, err)
 						return 2
 					}
 					// Re-check to report any remaining unfixed diagnostics.
 					diags, err = check(fixed, path)
 					if err != nil {
-						fmt.Fprintf(stderr, "pgtidy: %v\n", err)
+						_, _ = fmt.Fprintf(stderr, "pgtidy: %v\n", err)
 						return 2
 					}
 				}
@@ -144,7 +144,7 @@ func cmdLint(args []string, stdin io.Reader, stdout, stderr io.Writer) int {
 }
 
 func lintUsage(w io.Writer) {
-	fmt.Fprint(w, `Usage: pgtidy lint [flags] [file ...]
+	_, _ = fmt.Fprint(w, `Usage: pgtidy lint [flags] [file ...]
 
 Read SQL from files (or stdin) and report lint findings.
 

cmd/pgtidy/lsp.go

@@ -12,7 +12,7 @@ import (
 func cmdLsp(args []string, stdin io.Reader, stdout, stderr io.Writer) int {
 	for _, a := range args {
 		if a == "-h" || a == "--help" {
-			fmt.Fprintln(stdout, "pgtidy lsp — start the Language Server Protocol server (stdio transport)")
+			_, _ = fmt.Fprintln(stdout, "pgtidy lsp — start the Language Server Protocol server (stdio transport)")
 			return 0
 		}
 	}
@@ -21,7 +21,7 @@ func cmdLsp(args []string, stdin io.Reader, stdout, stderr io.Writer) int {
 		wd = "."
 	}
 	if err := lsp.Serve(context.Background(), stdin, stdout, wd); err != nil {
-		fmt.Fprintf(stderr, "pgtidy lsp: %v\n", err)
+		_, _ = fmt.Fprintf(stderr, "pgtidy lsp: %v\n", err)
 		return 1
 	}
 	return 0

cmd/pgtidy/main.go

@@ -29,20 +29,20 @@ func run(args []string, stdin io.Reader, stdout, stderr io.Writer) int {
 	case "config":
 		return cmdConfig(args[1:], stdin, stdout, stderr)
 	case "version", "--version", "-v":
-		fmt.Fprintf(stdout, "pgtidy %s\n", version)
+		_, _ = fmt.Fprintf(stdout, "pgtidy %s\n", version)
 		return 0
 	case "help", "-h", "--help":
 		usage(stdout)
 		return 0
 	default:
-		fmt.Fprintf(stderr, "pgtidy: unknown command %q\n", args[0])
+		_, _ = fmt.Fprintf(stderr, "pgtidy: unknown command %q\n", args[0])
 		usage(stderr)
 		return 2
 	}
 }
 
 func usage(w io.Writer) {
-	fmt.Fprint(w, `pgtidy — PostgreSQL formatter and linter
+	_, _ = fmt.Fprint(w, `pgtidy — PostgreSQL formatter and linter
 
 Usage:
   pgtidy fmt    [flags] [files...]  Format SQL/PL-pgSQL (stdin if no files)

pkg/config/config.go

@@ -61,21 +61,21 @@ type Style struct {
 	CustomTypeCase Case // user-defined / domain types not in the built-in set
 
 	// --- Query layout ---
-	Commas             CommaStyle
-	AlignColumns       bool      // pad SELECT list so values align
-	AlignLineComments  bool      // align trailing -- comments in a block
-	SelectAlignAs      bool      // pad between expression and AS in SELECT list
-	SetAlignEqual      bool      // align = in UPDATE SET list
-	IndentJoin         bool      // extra indentation for JOIN … ON lines
-	JoinIndentSize     int       // extra indent levels for JOINs (default 1)
-	WhereWrap          WrapMode  // always|when_long|never — each AND/OR on its own line
-	WhereAndOrIndent   bool      // AND/OR indented one level under WHERE
+	Commas            CommaStyle
+	AlignColumns      bool     // pad SELECT list so values align
+	AlignLineComments bool     // align trailing -- comments in a block
+	SelectAlignAs     bool     // pad between expression and AS in SELECT list
+	SetAlignEqual     bool     // align = in UPDATE SET list
+	IndentJoin        bool     // extra indentation for JOIN … ON lines
+	JoinIndentSize    int      // extra indent levels for JOINs (default 1)
+	WhereWrap         WrapMode // always|when_long|never — each AND/OR on its own line
+	WhereAndOrIndent  bool     // AND/OR indented one level under WHERE
 
 	// --- Subqueries ---
-	SubqueryOpening        Placement // opening ( placement: same_line|new_line
-	SubqueryContent        Placement // content indentation: same_line|new_line
-	SubqueryClosing        Placement // closing ) placement: same_line|new_line
-	SubquerySpaceBeforeParen bool    // space before ( in subqueries
+	SubqueryOpening          Placement // opening ( placement: same_line|new_line
+	SubqueryContent          Placement // content indentation: same_line|new_line
+	SubqueryClosing          Placement // closing ) placement: same_line|new_line
+	SubquerySpaceBeforeParen bool      // space before ( in subqueries
 
 	// --- INSERT ---
 	InsertCollapseValues bool // fold multiple VALUES rows onto fewer lines
@@ -85,11 +85,11 @@ type Style struct {
 	RoutineAsWrap   bool // newline before AS $$
 
 	// --- PL/pgSQL body ---
-	PlpgsqlMaxBlankLines     int  // max consecutive blank lines in body
-	PlpgsqlDeclareAlignType  bool // align type column in DECLARE block
-	PlpgsqlDeclareAlignEq    bool // align := / = in DECLARE block
-	PlpgsqlIfThenNewline     bool // THEN on its own line
-	PlpgsqlLoopCollapse      bool // collapse empty loop bodies to one line
+	PlpgsqlMaxBlankLines    int  // max consecutive blank lines in body
+	PlpgsqlDeclareAlignType bool // align type column in DECLARE block
+	PlpgsqlDeclareAlignEq   bool // align := / = in DECLARE block
+	PlpgsqlIfThenNewline    bool // THEN on its own line
+	PlpgsqlLoopCollapse     bool // collapse empty loop bodies to one line
 
 	// --- Expressions ---
 	BinaryOpAlign          bool      // align =, <>, || etc. vertically in WHERE/expr lists

pkg/format/dml.go

@@ -10,16 +10,13 @@ import (
 
 // isDMLStart reports whether toks begins with a DML statement keyword.
 func isDMLStart(toks []cst.Tok) bool {
-	for _, t := range toks {
-		if t.Tok.Kind == lexer.Ident {
-			switch lowerASCII(t.Tok.Text) {
-			case "select", "insert", "update", "delete", "with":
-				return true
-			}
-			return false
-		}
+	if len(toks) == 0 || toks[0].Tok.Kind != lexer.Ident {
 		return false
 	}
+	switch lowerASCII(toks[0].Tok.Text) {
+	case "select", "insert", "update", "delete", "with":
+		return true
+	}
 	return false
 }
 
@@ -510,13 +507,6 @@ func dmlSplitCommas(toks []cst.Tok) [][]cst.Tok {
 	return items
 }
 
-// dmlColList formats kwText followed by a comma-separated body.
-// One item: kept on the same line as the keyword.
-// Multiple items: each on its own line with the configured comma style.
-func dmlColList(kwText string, items [][]cst.Tok, st config.Style) string {
-	return dmlColListSelect(kwText, items, st)
-}
-
 // dmlColListSelect formats a SELECT / RETURNING column list with optional
 // align_columns and select_align_as settings.
 func dmlColListSelect(kwText string, items [][]cst.Tok, st config.Style) string {
@@ -627,7 +617,10 @@ func dmlColListSet(kwText string, items [][]cst.Tok, st config.Style) string {
 // alias names align vertically.
 func alignSelectItems(texts []string, st config.Style) []string {
 	// Split each text into (expr, " AS ", alias) or keep as-is.
-	type part struct{ expr, alias string; hasAs bool }
+	type part struct {
+		expr, alias string
+		hasAs       bool
+	}
 	parts := make([]part, len(texts))
 	maxExpr := 0
 	for i, t := range texts {

pkg/format/keywords.go

@@ -68,6 +68,6 @@ to_char to_date to_json to_jsonb to_number to_timestamp to_tsvector
 translate trim trunc unnest upper width_bucket
 `)
 
-func isKeyword(lower string) bool       { return keywords[lower] }
-func isTypeName(lower string) bool      { return typeNames[lower] }
-func isBuiltinFunc(lower string) bool   { return builtinFunctions[lower] }
+func isKeyword(lower string) bool     { return keywords[lower] }
+func isTypeName(lower string) bool    { return typeNames[lower] }
+func isBuiltinFunc(lower string) bool { return builtinFunctions[lower] }

pkg/lsp/server.go

@@ -89,12 +89,12 @@ func (s *server) handle(raw []byte) bool {
 		return true
 	case "textDocument/didOpen":
 		var p didOpenParams
-		json.Unmarshal(req.Params, &p)
+		_ = json.Unmarshal(req.Params, &p)
 		s.docs[p.TextDocument.URI] = p.TextDocument.Text
 		s.pushDiagnostics(p.TextDocument.URI, p.TextDocument.Text)
 	case "textDocument/didChange":
 		var p didChangeParams
-		json.Unmarshal(req.Params, &p)
+		_ = json.Unmarshal(req.Params, &p)
 		if len(p.ContentChanges) > 0 {
 			text := p.ContentChanges[len(p.ContentChanges)-1].Text
 			s.docs[p.TextDocument.URI] = text
@@ -104,7 +104,7 @@ func (s *server) handle(raw []byte) bool {
 		var p struct {
 			TextDocument textDocID `json:"textDocument"`
 		}
-		json.Unmarshal(req.Params, &p)
+		_ = json.Unmarshal(req.Params, &p)
 		delete(s.docs, p.TextDocument.URI)
 		delete(s.fixes, p.TextDocument.URI)
 		s.notify("textDocument/publishDiagnostics", publishDiagnosticsParams{
@@ -113,7 +113,7 @@ func (s *server) handle(raw []byte) bool {
 		})
 	case "textDocument/formatting":
 		var p formattingParams
-		json.Unmarshal(req.Params, &p)
+		_ = json.Unmarshal(req.Params, &p)
 		text, ok := s.docs[p.TextDocument.URI]
 		if !ok {
 			s.reply(req.ID, []textEdit{})
@@ -127,7 +127,7 @@ func (s *server) handle(raw []byte) bool {
 		s.reply(req.ID, []textEdit{fullReplace(text, formatted)})
 	case "textDocument/rangeFormatting":
 		var p rangeFormattingParams
-		json.Unmarshal(req.Params, &p)
+		_ = json.Unmarshal(req.Params, &p)
 		text, ok := s.docs[p.TextDocument.URI]
 		if !ok {
 			s.reply(req.ID, []textEdit{})
@@ -136,7 +136,7 @@ func (s *server) handle(raw []byte) bool {
 		s.reply(req.ID, s.rangeFormat(text, p.Range))
 	case "textDocument/codeAction":
 		var p codeActionParams
-		json.Unmarshal(req.Params, &p)
+		_ = json.Unmarshal(req.Params, &p)
 		s.handleCodeAction(req.ID, p)
 	case "$/cancelRequest": // ignore
 	default:
@@ -360,7 +360,7 @@ func (s *server) send(v interface{}) {
 	if err != nil {
 		return
 	}
-	fmt.Fprintf(s.w, "Content-Length: %d\r\n\r\n", len(data))
+	_, _ = fmt.Fprintf(s.w, "Content-Length: %d\r\n\r\n", len(data))
 	s.w.Write(data) //nolint:errcheck
 }
 

pkg/lsp/server_test.go

@@ -51,7 +51,7 @@ func readResp(t *testing.T, buf *bytes.Buffer) map[string]interface{} {
 		}
 		lenStr := string(data[idx+16 : idx+eol])
 		var n int
-		fmt.Sscanf(lenStr, "%d", &n)
+		_, _ = fmt.Sscanf(lenStr, "%d", &n)
 		sep := bytes.Index(data, []byte("\r\n\r\n"))
 		if sep < 0 || len(data) < sep+4+n {
 			time.Sleep(5 * time.Millisecond)
@@ -60,7 +60,7 @@ func readResp(t *testing.T, buf *bytes.Buffer) map[string]interface{} {
 		body := data[sep+4 : sep+4+n]
 		buf.Next(sep + 4 + n)
 		var result map[string]interface{}
-		json.Unmarshal(body, &result)
+		_ = json.Unmarshal(body, &result)
 		return result
 	}
 	t.Fatal("timeout waiting for response")

pkg/parser/parser.go

@@ -88,7 +88,7 @@ func parseCreateFunction(stmt []cst.Tok) (*cst.CreateFunction, bool) {
 	if i+1 < len(stmt) && stmt[i].Is("or") && stmt[i+1].Is("replace") {
 		i += 2
 	}
-	if i >= len(stmt) || !(stmt[i].Is("function") || stmt[i].Is("procedure")) {
+	if i >= len(stmt) || (!stmt[i].Is("function") && !stmt[i].Is("procedure")) {
 		return nil, false
 	}
 	i++

pkg/pgast/pgast.go

@@ -41,7 +41,7 @@ func FirstTokenOffset(sql string, start int) int {
 			}
 		case i+1 < n && sql[i] == '/' && sql[i+1] == '*':
 			i += 2
-			for i+1 < n && !(sql[i] == '*' && sql[i+1] == '/') {
+			for i+1 < n && (sql[i] != '*' || sql[i+1] != '/') {
 				i++
 			}
 			if i+1 < n {