add test

TEMPLATE.md

@@ -297,7 +297,7 @@ if self.Signature == BIG:   # where big is a constant or a eq pattern type value
 if self.Signature == 5:
   ...
 
-# example from bmp.yml
+# bit pattern matching example from bmp.yml
 u32 HeaderSize:
   eq 0000_000c: V2   # V2 automatically becomes a constant
   eq 0000_0028: V3

mapper/filelayout.go

@@ -678,6 +678,15 @@ func (fl *FileLayout) presentStruct(layout *Struct, cfg *PresentFileLayoutConfig
 	return res
 }
 
+// used for tests, buffered, returns when presentation is fully rendered.
+func (fl *FileLayout) PresentFullString(cfg *PresentFileLayoutConfig) string {
+	s := ""
+	for _, layout := range fl.Structs {
+		s += fl.presentStruct(layout, cfg) + "\n"
+	}
+	return s
+}
+
 func (fl *FileLayout) Present(cfg *PresentFileLayoutConfig) {
 	if fl == nil {
 		panic("Probably input yaml error, look for properly escaped strings and \" characters")

mapper/mapper_test.go

@@ -0,0 +1,52 @@
+package mapper
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/martinlindhe/feng/template"
+	"github.com/stretchr/testify/assert"
+)
+
+var testPResentConfig = PresentFileLayoutConfig{
+	ShowRaw: true,
+}
+
+func TestPresentData1(t *testing.T) {
+	templateData := `
+structs:
+  header:
+    u8 Flags:
+      bit b0001: B0
+      bit b0110: Rest
+      default: invalid
+    #if Flags == 6:   		# FIXME should error out on "unknown variable name 'Flags'"
+    if self.Flags == 6:
+      u8 Child: ??
+
+layout:
+  - header Header
+`
+	in := []byte{0x06, 0x03}
+	expected := `
+Header
+  [000000] Flags                          u8               6                              06
+           - B0                           bit 0:1          0
+           - Rest                         bit 1:2          3
+  [000001] Child                          u8               3                              03
+`
+
+	ds, err := template.UnmarshalTemplateIntoDataStructure([]byte(templateData), "")
+	assert.Equal(t, nil, err)
+
+	f := mockFile(t, "in", in)
+
+	fl, err := MapReader(&MapReaderConfig{
+		F:  f,
+		DS: ds,
+	})
+	assert.Equal(t, nil, err)
+
+	data := fl.PresentFullString(&testPResentConfig)
+	assert.Equal(t, strings.TrimSpace(expected), strings.TrimSpace(data))
+}

template/datastructures.go

@@ -12,7 +12,7 @@ import (
 // structure of a evaluated ./templates/ yaml file. see Template for the raw structure corresponding to the yaml file
 type DataStructure struct {
 
-	// constants derived from eq & bit matches
+	// constants derived from eq & bit pattern matches
 	Constants []Constant
 
 	// evaluated file structs
@@ -61,11 +61,13 @@ func NewDataStructureFrom(template *Template, basename string) (*DataStructure,
 	if DEBUG_PATTERNS {
 		log.Print("NewDataStructureFrom", basename)
 	}
+
 	constants, err := template.evaluateConstants()
 	if err != nil {
 		log.Warn().Err(err).Msgf("%s: evaluateConstants failed", basename)
 		return nil, err
 	}
+
 	structs, err := template.evaluateStructs()
 	if err != nil {
 		log.Warn().Err(err).Msgf("%s: evaluateStructs failed", basename)

template/template_test.go

@@ -12,8 +12,8 @@ import (
 	"github.com/martinlindhe/feng/value"
 )
 
-// evaluate all templates, validate some fields
-func TestEvaluateAllTemplates(t *testing.T) {
+// evaluate all templates to catch template parse errors, and validate some fields
+func TestValidateAllTemplates(t *testing.T) {
 
 	fs.WalkDir(feng.Templates, ".", func(path string, d fs.DirEntry, err2 error) error {
 		// cannot happen
@@ -108,5 +108,4 @@ layout:
 			{Kind: "other_segment", Range: "", Slice: true, Label: "other_segments"},
 		},
 	}, ds)
-
 }