data: blob extraction helper

atproto/data/basic_test.go

···
 
 	"github.com/bluesky-social/indigo/atproto/syntax"
 
+	"github.com/ipfs/go-cid"
 	"github.com/stretchr/testify/assert"
 )
 
···
 	_, err = json.Marshal(obj)
 	assert.NoError(err)
 }
+
+func TestExtractBlobs(t *testing.T) {
+	assert := assert.New(t)
+
+	cid1, _ := cid.Parse("bafkreiccldh766hwcnuxnf2wh6jgzepf2nlu2lvcllt63eww5p6chi4ity")
+	obj := map[string]interface{}{
+		"a": 5,
+		"b": 123,
+		"c": map[string]interface{}{
+			"blb": Blob{
+				Size:     567,
+				MimeType: "image/jpeg",
+				Ref:      CIDLink(cid1),
+			},
+		},
+		"d": []interface{}{
+			123,
+			Blob{
+				Size:     123,
+				MimeType: "image/png",
+				Ref:      CIDLink(cid1),
+			},
+		},
+	}
+	blbs := ExtractBlobs(obj)
+	assert.Equal(2, len(blbs))
+}

atproto/data/data.go

···
 	return out, nil
 }
 
+// Recursively finds all the "blob" objects from generic atproto data (which has already been parsed).
+//
+// Returns an array with all Blob instances; does not de-dupe.
+func ExtractBlobs(obj map[string]any) []Blob {
+	return extractBlobsAtom(obj)
+}
+
+func extractBlobsAtom(atom any) []Blob {
+	out := []Blob{}
+	switch v := atom.(type) {
+	case Blob:
+		out = append(out, v)
+	case []any:
+		for _, el := range v {
+			down := extractBlobsAtom(el)
+			for _, d := range down {
+				out = append(out, d)
+			}
+		}
+	case map[string]any:
+		for _, val := range v {
+			down := extractBlobsAtom(val)
+			for _, d := range down {
+				out = append(out, d)
+			}
+		}
+	default:
+	}
+	return out
+}
+
 // Serializes generic atproto data (object) to DAG-CBOR bytes
 //
 // Does not re-validate that data conforms to atproto data model, but does handle Blob, Bytes, and CIDLink as expected.

atproto/data/extract_test.go

···
 package data
 
 import (
-	"testing"
-	"os"
 	"io"
+	"os"
+	"testing"
 
 	"github.com/stretchr/testify/assert"
 )
···
 	if err != nil {
 		t.Fail()
 	}
-    cborBytes, err := io.ReadAll(inFile)
+	cborBytes, err := io.ReadAll(inFile)
 	if err != nil {
 		t.Fail()
 	}