feat: SimString - automatic embedding backed similarity search

.github/workflows/ci-go-unit-tests.yaml

@@ -39,5 +39,22 @@ jobs:
           go-version: 1.25.0
           cache-dependency-path: go.sum
 
+      - name: Set up Dgraph
+        if: matrix.os == 'linux'
+        run: |
+          docker run -d --name dgraph-standalone -p 9080:9080 -p 8080:8080 dgraph/standalone:latest
+          echo "Waiting for Dgraph to be ready..."
+          for i in {1..30}; do
+            if curl -s http://localhost:8080/health > /dev/null; then
+              echo "Dgraph is ready!"
+              break
+            fi
+            echo "Attempt $i: Dgraph not ready, waiting..."
+            sleep 2
+          done
+          sleep 5
+
       - name: Run Unit Tests
+        env:
+          MODUSGRAPH_TEST_ADDR: ${{ matrix.os == 'linux' && 'localhost:9080' || '' }}
         run: go test -short -race -v .

client.go

@@ -113,14 +113,16 @@ type StructValidator interface {
 // namespace: the namespace for the client.
 // logger: the logger for the client.
 // validator: the validator instance for struct validation.
+// embeddingProvider: optional provider for automatic SimString vector embeddings.
 type clientOptions struct {
-	autoSchema       bool
-	poolSize         int
-	maxEdgeTraversal int
-	cacheSizeMB      int
-	namespace        string
-	logger           logr.Logger
-	validator        StructValidator
+	autoSchema        bool
+	poolSize          int
+	maxEdgeTraversal  int
+	cacheSizeMB       int
+	namespace         string
+	logger            logr.Logger
+	validator         StructValidator
+	embeddingProvider EmbeddingProvider
 }
 
 // ClientOpt is a function that configures a client
@@ -182,6 +184,17 @@ func WithValidator(v StructValidator) ClientOpt {
 	}
 }
 
+// WithEmbeddingProvider sets the EmbeddingProvider used to automatically generate
+// and maintain shadow float32vector predicates for SimString fields tagged with
+// `dgraph:"embedding"`. When set, Insert, Upsert, and Update operations will
+// call the provider to embed any SimString values and persist the resulting
+// vectors alongside the primary string predicates.
+func WithEmbeddingProvider(p EmbeddingProvider) ClientOpt {
+	return func(o *clientOptions) {
+		o.embeddingProvider = p
+	}
+}
+
 // NewValidator creates a new validator instance with default settings.
 // This is a convenience function for creating a validator to use with WithValidator.
 // It returns a *validator.Validate from github.com/go-playground/validator/v10.
@@ -308,8 +321,18 @@ func (c client) key() string {
 	if c.options.validator != nil {
 		validatorKey = fmt.Sprintf("%p", c.options.validator)
 	}
-	return fmt.Sprintf("%s:%t:%d:%d:%d:%s:%s", c.uri, c.options.autoSchema, c.options.poolSize,
-		c.options.maxEdgeTraversal, c.options.cacheSizeMB, c.options.namespace, validatorKey)
+	embeddingKey := "nil"
+	if c.options.embeddingProvider != nil {
+		embeddingKey = fmt.Sprintf("%p", c.options.embeddingProvider)
+	}
+	return fmt.Sprintf("%s:%t:%d:%d:%d:%s:%s:%s", c.uri, c.options.autoSchema, c.options.poolSize,
+		c.options.maxEdgeTraversal, c.options.cacheSizeMB, c.options.namespace, validatorKey, embeddingKey)
+}
+
+// embeddingProvider implements the embeddingClient interface, exposing the
+// configured EmbeddingProvider to package-level helpers like SimilarToText.
+func (c client) embeddingProvider() EmbeddingProvider {
+	return c.options.embeddingProvider
 }
 
 func checkPointer(obj any) error {
@@ -458,16 +481,33 @@ func (c client) Query(ctx context.Context, model any) *dg.Query {
 
 // UpdateSchema implements updating the Dgraph schema. Pass one or more
 // objects that will be used to generate the schema.
+// If any object contains SimString fields tagged `dgraph:"embedding"`, the
+// corresponding shadow float32vector predicates (<field>__vec) are also registered.
 func (c client) UpdateSchema(ctx context.Context, obj ...any) error {
-	client, err := c.pool.get()
+	dgClient, err := c.pool.get()
 	if err != nil {
 		c.logger.Error(err, "Failed to get client from pool")
 		return err
 	}
-	defer c.pool.put(client)
+	defer c.pool.put(dgClient)
+
+	if _, err = dg.CreateSchema(dgClient, obj...); err != nil {
+		return err
+	}
+
+	// Collect shadow vector schema lines for SimString fields across all objects.
+	var vecSchema strings.Builder
+	for _, o := range obj {
+		for _, info := range collectSimFields(o) {
+			vecSchema.WriteString(buildVecSchemaStatement(info))
+			vecSchema.WriteString("\n")
+		}
+	}
+	if vecSchema.Len() == 0 {
+		return nil
+	}
 
-	_, err = dg.CreateSchema(client, obj...)
-	return err
+	return dgClient.Alter(ctx, &api.Operation{Schema: vecSchema.String()})
 }
 
 // GetSchema implements retrieving the Dgraph schema.