Some fixes for staticcheck (#2006)

* Implement some staticcheck fixes

* make fmt

* more

* more staticcheck

CLAUDE.md

@@ -4,6 +4,30 @@
 
 Miller is a command-line data processing tool for working with CSV, TSV, JSON, and other data formats. It's written in Go (v1.18+) and provides SQL-like operations on data.
 
+## Initial Setup
+
+### Setting Up staticcheck
+
+The `make staticcheck` target requires the staticcheck tool. To set it up:
+
+```bash
+go install honnef.co/go/tools/cmd/staticcheck@latest
+```
+
+This installs staticcheck to `~/go/bin/` (the default Go binaries directory). For `make staticcheck` to work, you need `~/go/bin` in your `PATH`.
+
+**Add to your shell profile** (`.bashrc`, `.zshrc`, or equivalent):
+```bash
+export PATH="$PATH:$HOME/go/bin"
+```
+
+**Verify the installation:**
+```bash
+staticcheck -version
+```
+
+If this works, you can use `make staticcheck` without any further setup.
+
 ## Build & Test
 
 ### Building
@@ -23,7 +47,7 @@ make bench          # Run benchmarks
 ### Code Quality
 ```bash
 make fmt            # Format code with go fmt
-make staticcheck    # Run static analysis (requires: go install honnef.co/go/tools/cmd/staticcheck@latest)
+make staticcheck    # Run static analysis (see Initial Setup section above)
 ```
 
 ### Full Developer Workflow

pkg/go-csv/csv_reader.go

@@ -307,7 +307,7 @@ func (r *Reader) readRecord(dst []string) ([]string, error) {
 	// Read line (automatically skipping past empty lines and any comments).
 	var line []byte
 	var errRead error
-	for errRead == nil {
+
 	line, errRead = r.readLine()
 
 	// MILLER-SPECIFIC UPDATE: DO NOT DO THIS
@@ -331,8 +331,7 @@ func (r *Reader) readRecord(dst []string) ([]string, error) {
 	if r.Comment != 0 && nextRune(line) == r.Comment {
 		return []string{string(line)}, nil
 	}
-		break
-	}
+
 	if errRead == io.EOF {
 		return nil, errRead
 	}

pkg/input/fixed_width_splitter.go

@@ -41,7 +41,7 @@ func NewFixedWidthSplitter(spec, referenceRow string) (*fixedWidthSplitter, erro
 	} else if spec == "right-align-multi-word" {
 		indexes = parseRightAlign(referenceRow, true)
 	} else {
-		return nil, fmt.Errorf("Unknown spec: %v", spec)
+		return nil, fmt.Errorf("unknown spec: %v", spec)
 	}
 	return &fixedWidthSplitter{indexes: indexes}, nil
 

pkg/input/record_reader_pprint.go

@@ -229,7 +229,7 @@ func (reader *RecordReaderPprintFixedSplit) getRecords(
 		} else {
 			if !reader.readerOptions.AllowRaggedCSVInput && len(reader.headerStrings) != len(fields) {
 				err := fmt.Errorf(
-					"Fixed-width header/data length mismatch %d != %d at filename %s line %d",
+					"fixed-width header/data length mismatch %d != %d at filename %s line %d",
 					len(reader.headerStrings), len(fields), filename, reader.inputLineNumber,
 				)
 				errorChannel <- err

pkg/mlrval/mlrmap_flatten_unflatten.go

@@ -151,7 +151,7 @@ func (mlrmap *Mlrmap) CopyUnflattened(
 
 		// Check for "" in any of the split pieces; treat the field as terminal if so.
 		legitDots := true
-		for i, _ := range arrayval {
+		for i := range arrayval {
 			piece := arrayval[i].String()
 			if piece == "" {
 				legitDots = false

pkg/mlrval/mlrval_collections.go

@@ -338,7 +338,7 @@ func putIndexedOnArray(
 			return errors.New("zero indices are not supported. Indices are 1-up")
 		}
 		if mindex.intf.(int64) < 0 {
-			return errors.New("Cannot use negative indices to auto-lengthen arrays")
+			return errors.New("cannot use negative indices to auto-lengthen arrays")
 		}
 		// Array is [a,b,c] with mindices 1,2,3. Length is 3. Zindices are 0,1,2.
 		// Given mindex is 4.
@@ -371,7 +371,7 @@ func putIndexedOnArray(
 	} else if mindex.intf.(int64) == 0 {
 		return errors.New("zero indices are not supported. Indices are 1-up")
 	} else if mindex.intf.(int64) < 0 {
-		return errors.New("Cannot use negative indices to auto-lengthen arrays")
+		return errors.New("cannot use negative indices to auto-lengthen arrays")
 	} else {
 		// Already allocated but needs to be longer
 		LengthenMlrvalArray(baseArray, int(mindex.intf.(int64)))

pkg/mlrval/mlrval_json.go

@@ -27,7 +27,7 @@ const (
 	JSON_MULTILINE   = 2
 )
 
-var prematureEofError error = errors.New("JSON parser: unexpected premature EOF")
+var errPrematureEOF = errors.New("JSON parser: unexpected premature EOF")
 
 // The JSON decoder (https://golang.org/pkg/encoding/json/#Decoder) is quite
 // nice. What we can have is:
@@ -192,7 +192,7 @@ func MlrvalDecodeFromJSON(decoder *json.Decoder) (
 			for decoder.More() {
 				element, eof, err := MlrvalDecodeFromJSON(decoder)
 				if eof {
-					return nil, false, prematureEofError
+					return nil, false, errPrematureEOF
 				}
 				if err != nil {
 					return nil, false, err
@@ -205,7 +205,7 @@ func MlrvalDecodeFromJSON(decoder *json.Decoder) (
 			for decoder.More() {
 				key, eof, err := MlrvalDecodeFromJSON(decoder)
 				if eof {
-					return nil, false, prematureEofError
+					return nil, false, errPrematureEOF
 				}
 				if err != nil {
 					return nil, false, err
@@ -219,7 +219,7 @@ func MlrvalDecodeFromJSON(decoder *json.Decoder) (
 
 				value, eof, err := MlrvalDecodeFromJSON(decoder)
 				if eof {
-					return nil, false, prematureEofError
+					return nil, false, errPrematureEOF
 				}
 				if err != nil {
 					return nil, false, err
@@ -296,7 +296,7 @@ func (mv *Mlrval) marshalJSONAux(
 	case MT_DIM: // MT_DIM is one past the last valid type
 		return "", fmt.Errorf("internal coding error detected")
 	}
-	return "", fmt.Errorf("Internal coding error detected")
+	return "", fmt.Errorf("internal coding error detected")
 }
 
 // TYPE-SPECIFIC MARSHALERS

pkg/output/record_writer_dcf.go

@@ -52,7 +52,7 @@ func dcfValueString(mv *mlrval.Mlrval) string {
 	}
 	if mv.IsArray() {
 		arr := mv.GetArray()
-		if arr == nil || len(arr) == 0 {
+		if len(arr) == 0 {
 			return ""
 		}
 		parts := make([]string, 0, len(arr))

pkg/parsing/token/token.go

@@ -123,7 +123,7 @@ func (t *Token) Int64Value() (int64, error) {
 func (t *Token) UTF8Rune() (rune, error) {
 	r, _ := utf8.DecodeRune(t.Lit)
 	if r == utf8.RuneError {
-		err := fmt.Errorf("Invalid rune")
+		err := fmt.Errorf("invalid rune")
 		return r, err
 	}
 	return r, nil

pkg/transformers/check.go

@@ -58,9 +58,10 @@ func transformerCheckParseCLI(
 			transformerCheckUsage(os.Stdout)
 			return nil, cli.ErrHelpRequested
 
-		}
+		} else {
 			return nil, cli.VerbErrorf(verbNameCheck, "option \"%s\" not recognized", opt)
 		}
+	}
 
 	*pargi = argi
 	if !doConstruct { // All transformers must do this for main command-line parsing

pkg/transformers/group_by.go

@@ -54,9 +54,10 @@ func transformerGroupByParseCLI(
 			transformerGroupByUsage(os.Stdout)
 			return nil, cli.ErrHelpRequested
 
-		}
+		} else {
 			return nil, cli.VerbErrorf(verbNameGroupBy, "option \"%s\" not recognized", opt)
 		}
+	}
 
 	// Get the group-by field names from the command line
 	if argi >= argc {

pkg/transformers/group_like.go

@@ -54,9 +54,10 @@ func transformerGroupLikeParseCLI(
 			transformerGroupLikeUsage(os.Stdout)
 			return nil, cli.ErrHelpRequested
 
-		}
+		} else {
 			return nil, cli.VerbErrorf(verbNameGroupLike, "option \"%s\" not recognized", opt)
 		}
+	}
 
 	*pargi = argi
 	if !doConstruct { // All transformers must do this for main command-line parsing

pkg/transformers/label.go

@@ -58,9 +58,10 @@ func transformerLabelParseCLI(
 			transformerLabelUsage(os.Stdout)
 			return nil, cli.ErrHelpRequested
 
-		}
+		} else {
 			return nil, cli.VerbErrorf(verbNameLabel, "option \"%s\" not recognized", opt)
 		}
+	}
 
 	// Get the label field names from the command line
 	if argi >= argc {

pkg/transformers/latin1_to_utf8.go

@@ -56,9 +56,10 @@ func transformerLatin1ToUTF8ParseCLI(
 			transformerLatin1ToUTF8Usage(os.Stdout)
 			return nil, cli.ErrHelpRequested
 
-		}
+		} else {
 			return nil, cli.VerbErrorf(verbNameLatin1ToUTF8, "option \"%s\" not recognized", opt)
 		}
+	}
 
 	*pargi = argi
 	if !doConstruct { // All transformers must do this for main command-line parsing

pkg/transformers/nothing.go

@@ -53,10 +53,11 @@ func transformerNothingParseCLI(
 		if opt == "-h" || opt == "--help" {
 			transformerNothingUsage(os.Stdout)
 			return nil, cli.ErrHelpRequested
-		}
+		} else {
 			transformerNothingUsage(os.Stderr)
 			return nil, fmt.Errorf("%s %s: option \"%s\" not recognized", "mlr", verbNameNothing, opt)
 		}
+	}
 
 	*pargi = argi
 	if !doConstruct { // All transformers must do this for main command-line parsing

pkg/transformers/regularize.go

@@ -55,9 +55,10 @@ func transformerRegularizeParseCLI(
 			transformerRegularizeUsage(os.Stdout)
 			return nil, cli.ErrHelpRequested
 
-		}
+		} else {
 			return nil, cli.VerbErrorf(verbNameRegularize, "option \"%s\" not recognized", opt)
 		}
+	}
 
 	*pargi = argi
 	if !doConstruct { // All transformers must do this for main command-line parsing

pkg/transformers/remove_empty_columns.go

@@ -54,9 +54,10 @@ func transformerRemoveEmptyColumnsParseCLI(
 			transformerRemoveEmptyColumnsUsage(os.Stdout)
 			return nil, cli.ErrHelpRequested
 
-		}
+		} else {
 			return nil, cli.VerbErrorf(verbNameRemoveEmptyColumns, "option \"%s\" not recognized", opt)
 		}
+	}
 
 	*pargi = argi
 	if !doConstruct { // All transformers must do this for main command-line parsing

pkg/transformers/sec2gmtdate.go

@@ -57,9 +57,10 @@ func transformerSec2GMTDateParseCLI(
 			transformerSec2GMTDateUsage(os.Stdout)
 			return nil, cli.ErrHelpRequested
 
-		}
+		} else {
 			return nil, cli.VerbErrorf(verbNameSec2GMTDate, "option \"%s\" not recognized", opt)
 		}
+	}
 
 	if argi >= argc {
 		return nil, cli.VerbErrorf(verbNameSec2GMTDate, "field names required")

pkg/transformers/shuffle.go

@@ -57,9 +57,10 @@ func transformerShuffleParseCLI(
 			transformerShuffleUsage(os.Stdout)
 			return nil, cli.ErrHelpRequested
 
-		}
+		} else {
 			return nil, cli.VerbErrorf(verbNameShuffle, "option \"%s\" not recognized", opt)
 		}
+	}
 
 	*pargi = argi
 	if !doConstruct { // All transformers must do this for main command-line parsing

pkg/transformers/skip_trivial_records.go

@@ -54,9 +54,10 @@ func transformerSkipTrivialRecordsParseCLI(
 			transformerSkipTrivialRecordsUsage(os.Stdout)
 			return nil, cli.ErrHelpRequested
 
-		}
+		} else {
 			return nil, cli.VerbErrorf(verbNameSkipTrivialRecords, "option \"%s\" not recognized", opt)
 		}
+	}
 
 	*pargi = argi
 	if !doConstruct { // All transformers must do this for main command-line parsing

pkg/transformers/tac.go

@@ -53,9 +53,10 @@ func transformerTacParseCLI(
 			transformerTacUsage(os.Stdout)
 			return nil, cli.ErrHelpRequested
 
-		}
+		} else {
 			return nil, cli.VerbErrorf(verbNameTac, "option \"%s\" not recognized", opt)
 		}
+	}
 
 	*pargi = argi
 	if !doConstruct { // All transformers must do this for main command-line parsing

pkg/transformers/utf8_to_latin1.go

@@ -56,9 +56,10 @@ func transformerUTF8ToLatin1ParseCLI(
 			transformerUTF8ToLatin1Usage(os.Stdout)
 			return nil, cli.ErrHelpRequested
 
-		}
+		} else {
 			return nil, cli.VerbErrorf(verbNameUTF8ToLatin1, "option \"%s\" not recognized", opt)
 		}
+	}
 
 	*pargi = argi
 	if !doConstruct { // All transformers must do this for main command-line parsing