fix apk decode for older data shapes (anchore#1341)

Signed-off-by: Alex Goodman <alex.goodman@anchore.com>

Signed-off-by: Alex Goodman <alex.goodman@anchore.com>

syft/pkg/apk_metadata.go

@@ -1,8 +1,13 @@
 package pkg
 
 import (
+	"encoding/json"
+	"fmt"
+	"reflect"
 	"sort"
+	"strings"
 
+	"github.com/mitchellh/mapstructure"
 	"github.com/scylladb/go-set/strset"
 
 	"github.com/anchore/syft/syft/file"
@@ -35,6 +40,58 @@ type ApkMetadata struct {
 	Files         []ApkFileRecord `json:"files"`
 }
 
+type spaceDelimitedStringSlice []string
+
+func (m *ApkMetadata) UnmarshalJSON(data []byte) error {
+	var fields []reflect.StructField
+	t := reflect.TypeOf(ApkMetadata{})
+	for i := 0; i < t.NumField(); i++ {
+		f := t.Field(i)
+		if f.Name == "Dependencies" {
+			f.Type = reflect.TypeOf(spaceDelimitedStringSlice{})
+		}
+		fields = append(fields, f)
+	}
+	apkMetadata := reflect.StructOf(fields)
+	inst := reflect.New(apkMetadata)
+	if err := json.Unmarshal(data, inst.Interface()); err != nil {
+		return err
+	}
+
+	return mapstructure.Decode(inst.Elem().Interface(), m)
+}
+
+func (a *spaceDelimitedStringSlice) UnmarshalJSON(data []byte) error {
+	var jsonObj interface{}
+
+	if err := json.Unmarshal(data, &jsonObj); err != nil {
+		return err
+	}
+
+	switch obj := jsonObj.(type) {
+	case string:
+		if obj == "" {
+			*a = nil
+		} else {
+			*a = strings.Split(obj, " ")
+		}
+		return nil
+	case []interface{}:
+		s := make([]string, 0, len(obj))
+		for _, v := range obj {
+			value, ok := v.(string)
+			if !ok {
+				return fmt.Errorf("invalid type for string array element: %T", v)
+			}
+			s = append(s, value)
+		}
+		*a = s
+		return nil
+	default:
+		return fmt.Errorf("invalid type for string array: %T", obj)
+	}
+}
+
 // ApkFileRecord represents a single file listing and metadata from a APK DB entry (which may have many of these file records).
 type ApkFileRecord struct {
 	Path        string       `json:"path"`

syft/pkg/apk_metadata_test.go

@@ -0,0 +1,156 @@
+package pkg
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestApkMetadata_UnmarshalJSON(t *testing.T) {
+	tests := []struct {
+		name    string
+		input   string
+		want    ApkMetadata
+		wantErr require.ErrorAssertionFunc
+	}{
+		{
+			name:  "empty",
+			input: "{}",
+			want:  ApkMetadata{},
+		},
+		{
+			name: "string array dependencies",
+			input: `{
+"package": "scanelf",
+"originPackage": "pax-utils",
+"maintainer": "Natanael Copa <ncopa@alpinelinux.org>",
+"version": "1.3.4-r0",
+"license": "GPL-2.0-only",
+"architecture": "x86_64",
+"url": "https://wiki.gentoo.org/wiki/Hardened/PaX_Utilities",
+"description": "Scan ELF binaries for stuff",
+"size": 36745,
+"installedSize": 94208,
+"pullChecksum": "Q1Gcqe+ND8DFOlhM3R0o5KyZjR2oE=",
+"gitCommitOfApkPort": "d7ae612a3cc5f827289d915783b4cbf8c7207947",
+"files": [
+ {
+  "path": "/usr"
+ }
+],
+"pullDependencies": ["foo", "bar"]
+}`,
+			want: ApkMetadata{
+				Package:       "scanelf",
+				OriginPackage: "pax-utils",
+				Maintainer:    "Natanael Copa <ncopa@alpinelinux.org>",
+				Version:       "1.3.4-r0",
+				License:       "GPL-2.0-only",
+				Architecture:  "x86_64",
+				URL:           "https://wiki.gentoo.org/wiki/Hardened/PaX_Utilities",
+				Description:   "Scan ELF binaries for stuff",
+				Size:          36745,
+				InstalledSize: 94208,
+				Dependencies:  []string{"foo", "bar"},
+				Checksum:      "Q1Gcqe+ND8DFOlhM3R0o5KyZjR2oE=",
+				GitCommit:     "d7ae612a3cc5f827289d915783b4cbf8c7207947",
+				Files:         []ApkFileRecord{{Path: "/usr"}},
+			},
+		},
+		{
+			name: "single string dependencies",
+			input: `{
+"package": "scanelf",
+"originPackage": "pax-utils",
+"maintainer": "Natanael Copa <ncopa@alpinelinux.org>",
+"version": "1.3.4-r0",
+"license": "GPL-2.0-only",
+"architecture": "x86_64",
+"url": "https://wiki.gentoo.org/wiki/Hardened/PaX_Utilities",
+"description": "Scan ELF binaries for stuff",
+"size": 36745,
+"installedSize": 94208,
+"pullChecksum": "Q1Gcqe+ND8DFOlhM3R0o5KyZjR2oE=",
+"gitCommitOfApkPort": "d7ae612a3cc5f827289d915783b4cbf8c7207947",
+"files": [
+ {
+  "path": "/usr"
+ }
+],
+"pullDependencies": "foo bar"
+}`,
+			want: ApkMetadata{
+				Package:       "scanelf",
+				OriginPackage: "pax-utils",
+				Maintainer:    "Natanael Copa <ncopa@alpinelinux.org>",
+				Version:       "1.3.4-r0",
+				License:       "GPL-2.0-only",
+				Architecture:  "x86_64",
+				URL:           "https://wiki.gentoo.org/wiki/Hardened/PaX_Utilities",
+				Description:   "Scan ELF binaries for stuff",
+				Size:          36745,
+				InstalledSize: 94208,
+				Dependencies:  []string{"foo", "bar"},
+				Checksum:      "Q1Gcqe+ND8DFOlhM3R0o5KyZjR2oE=",
+				GitCommit:     "d7ae612a3cc5f827289d915783b4cbf8c7207947",
+				Files:         []ApkFileRecord{{Path: "/usr"}},
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if tt.wantErr == nil {
+				tt.wantErr = require.NoError
+			}
+			var got ApkMetadata
+			err := json.Unmarshal([]byte(tt.input), &got)
+			tt.wantErr(t, err)
+			if err != nil {
+				return
+			}
+			assert.Equal(t, tt.want, got)
+		})
+	}
+}
+
+func TestSpaceDelimitedStringSlice_UnmarshalJSON(t *testing.T) {
+	tests := []struct {
+		name    string
+		data    string
+		want    []string
+		wantErr require.ErrorAssertionFunc
+	}{
+		{
+			name: "empty string",
+			data: `""`,
+			want: nil,
+		},
+		{
+			name: "single string with one elements",
+			data: `"foo"`,
+			want: []string{"foo"},
+		},
+		{
+			name: "single string with multiple elements",
+			data: `"foo bar"`,
+			want: []string{"foo", "bar"},
+		},
+		{
+			name: "string array",
+			data: `["foo", "bar"]`,
+			want: []string{"foo", "bar"},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if tt.wantErr == nil {
+				tt.wantErr = require.NoError
+			}
+			element := spaceDelimitedStringSlice{}
+			tt.wantErr(t, element.UnmarshalJSON([]byte(tt.data)))
+			assert.Equal(t, tt.want, []string(element))
+		})
+	}
+}