From 0ee7f82d681048df00a73494caebed6d0ecb6ff5 Mon Sep 17 00:00:00 2001
From: Daniel Skinner <daniel@dasa.cc>
Date: Fri, 26 Feb 2016 18:54:50 -0600
Subject: [PATCH] internal/binres: move test-related code out of package source

Change-Id: I5989c9395ff1aa40869ccd123cb277eea992a64c
Reviewed-on: https://go-review.googlesource.com/19991
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
---
 internal/binres/binres.go      | 38 ++++++++++++++++------------------
 internal/binres/binres_test.go | 25 ++++++++++++++++++++--
 2 files changed, 41 insertions(+), 22 deletions(-)

diff --git a/internal/binres/binres.go b/internal/binres/binres.go
index a796efa..3fca41c 100644
--- a/internal/binres/binres.go
+++ b/internal/binres/binres.go
@@ -159,11 +159,6 @@ type XML struct {
 	stack []*Element
 }
 
-// TODO this is used strictly for querying in tests and dependent on
-// current XML.UnmarshalBinary implementation. Look into moving directly
-// into tests.
-var debugIndices = make(map[encoding.BinaryMarshaler]int)
-
 const (
 	androidSchema = "http://schemas.android.com/apk/res/android"
 	toolsSchema   = "http://schemas.android.com/tools"
@@ -568,33 +563,36 @@ func UnmarshalXML(r io.Reader) (*XML, error) {
 	return bx, nil
 }
 
-func (bx *XML) UnmarshalBinary(bin []byte) error {
-	buf := bin
-	if err := (&bx.chunkHeader).UnmarshalBinary(bin); err != nil {
+// UnmarshalBinary decodes all resource chunks in buf returning any error encountered.
+func (bx *XML) UnmarshalBinary(buf []byte) error {
+	if err := (&bx.chunkHeader).UnmarshalBinary(buf); err != nil {
 		return err
 	}
 	buf = buf[8:]
-
-	// TODO this is tracked strictly for querying in tests; look into moving this
-	// functionality directly into tests if possible.
-	debugIndex := 8
-
 	for len(buf) > 0 {
-		t := ResType(btou16(buf))
-		k, err := bx.kind(t)
+		k, err := bx.unmarshalBinaryKind(buf)
 		if err != nil {
 			return err
 		}
-		if err := k.UnmarshalBinary(buf); err != nil {
-			return err
-		}
-		debugIndices[k.(encoding.BinaryMarshaler)] = debugIndex
-		debugIndex += int(k.size())
 		buf = buf[k.size():]
 	}
 	return nil
 }
 
+// unmarshalBinaryKind decodes and stores the first resource chunk of bin.
+// It returns the unmarshaler interface and any error encountered.
+// If k.size() < len(bin), subsequent chunks can be decoded at bin[k.size():].
+func (bx *XML) unmarshalBinaryKind(bin []byte) (k unmarshaler, err error) {
+	k, err = bx.kind(ResType(btou16(bin)))
+	if err != nil {
+		return nil, err
+	}
+	if err = k.UnmarshalBinary(bin); err != nil {
+		return nil, err
+	}
+	return k, nil
+}
+
 func (bx *XML) kind(t ResType) (unmarshaler, error) {
 	switch t {
 	case ResStringPool:
diff --git a/internal/binres/binres_test.go b/internal/binres/binres_test.go
index bfd2b51..f7c5069 100644
--- a/internal/binres/binres_test.go
+++ b/internal/binres/binres_test.go
@@ -105,6 +105,27 @@ func TestBootstrap(t *testing.T) {
 		log.Fatal(err)
 	}
 
+	// unmarshal binary xml and store byte indices of decoded resources.
+	debugIndices := make(map[encoding.BinaryMarshaler]int)
+	trackUnmarshal := func(buf []byte) (*XML, error) {
+		bx := new(XML)
+		if err := (&bx.chunkHeader).UnmarshalBinary(buf); err != nil {
+			return nil, err
+		}
+		buf = buf[8:]
+		debugIndex := 8
+		for len(buf) > 0 {
+			k, err := bx.unmarshalBinaryKind(buf)
+			if err != nil {
+				return nil, err
+			}
+			debugIndices[k.(encoding.BinaryMarshaler)] = debugIndex
+			debugIndex += k.size()
+			buf = buf[k.size():]
+		}
+		return bx, nil
+	}
+
 	checkMarshal := func(res encoding.BinaryMarshaler, bsize int) {
 		b, err := res.MarshalBinary()
 		if err != nil {
@@ -151,8 +172,8 @@ func TestBootstrap(t *testing.T) {
 		}
 	}
 
-	bxml := new(XML)
-	if err := bxml.UnmarshalBinary(bin); err != nil {
+	bxml, err := trackUnmarshal(bin)
+	if err != nil {
 		t.Fatal(err)
 	}