fixedlength file decl (#111)

Author: jf-tech

extensions/omniv21/fileformat/fixedlength/decl.go

@@ -0,0 +1,64 @@
+package fixedlength
+
+import (
+	"fmt"
+
+	"github.com/jf-tech/go-corelib/caches"
+)
+
+type byHeaderFooterDecl struct {
+	Header string `json:"header"`
+	Footer string `json:"footer"`
+}
+
+type columnDecl struct {
+	Name     string  `json:"name"`
+	StartPos int     `json:"start_pos"` // 1-based. and rune-based.
+	Length   int     `json:"length"`    // rune-based length.
+	Line     *string `json:"line"`
+}
+
+type envelopeDecl struct {
+	Name           *string             `json:"name"`
+	ByHeaderFooter *byHeaderFooterDecl `json:"by_header_footer"`
+	ByRows         *int                `json:"by_rows"`
+	NotTarget      bool                `json:"not_target"`
+	Columns        []*columnDecl       `json:"columns"`
+}
+
+type fileDecl struct {
+	Envelopes []*envelopeDecl `json:"envelopes"`
+}
+
+func (c *columnDecl) lineMatch(line []byte) bool {
+	if c.Line == nil {
+		return true
+	}
+	// validated in validation code.
+	r, _ := caches.GetRegex(*c.Line)
+	return r.Match(line)
+}
+
+func (c *columnDecl) lineToColumn(line []rune) []rune {
+	// StartPos is 1-based and its value >= 1 guaranteed by json schema validation done earlier.
+	startPosZeroBased := c.StartPos - 1
+	// If [startPosZeroBased, c.Length] is partially out of range, we'll return whatever is
+	// in range; if [startPosZeroBased, c.Length] is fully out of range, we'll return "".
+	switch {
+	case startPosZeroBased+c.Length <= len(line):
+		return line[startPosZeroBased : startPosZeroBased+c.Length]
+	case startPosZeroBased < len(line):
+		return line[startPosZeroBased:]
+	}
+	return nil
+}
+
+func (e *envelopeDecl) byRows() int {
+	if e.ByHeaderFooter != nil {
+		panic(fmt.Sprintf("envelope '%s' type is not 'by_rows'", *e.Name))
+	}
+	if e.ByRows == nil {
+		return 1
+	}
+	return *e.ByRows
+}

extensions/omniv21/fileformat/fixedlength/decl_test.go

@@ -0,0 +1,32 @@
+package fixedlength
+
+import (
+	"testing"
+
+	"github.com/jf-tech/go-corelib/strs"
+	"github.com/jf-tech/go-corelib/testlib"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestColumnDecl_LineMatch(t *testing.T) {
+	assert.True(t, (&columnDecl{}).lineMatch([]byte("test")))
+	assert.False(t, (&columnDecl{Line: strs.StrPtr("^ABC.*$")}).lineMatch([]byte("test")))
+	assert.True(t, (&columnDecl{Line: strs.StrPtr("^ABC.*$")}).lineMatch([]byte("ABCDEFG")))
+}
+
+func TestColumnDecl_LineToColumn(t *testing.T) {
+	decl := func(start, length int) *columnDecl {
+		return &columnDecl{StartPos: start, Length: length}
+	}
+	assert.Nil(t, decl(10, 4).lineToColumn([]rune("test")))                 // fully out of range
+	assert.Equal(t, []rune("st"), decl(3, 4).lineToColumn([]rune("test")))  // partially out of range
+	assert.Equal(t, []rune("tes"), decl(1, 3).lineToColumn([]rune("test"))) // fully in range
+}
+
+func TestEnvelopeDecl_ByRows(t *testing.T) {
+	assert.PanicsWithValue(t, `envelope 'env1' type is not 'by_rows'`, func() {
+		(&envelopeDecl{Name: strs.StrPtr("env1"), ByHeaderFooter: &byHeaderFooterDecl{}}).byRows()
+	})
+	assert.Equal(t, 1, (&envelopeDecl{}).byRows())
+	assert.Equal(t, 12, (&envelopeDecl{ByRows: testlib.IntPtr(12)}).byRows())
+}