fix(modelconfig): return empty architecture when Mistral Architectures is missing

pkg/hfutil/modelconfig/mistral.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"os"
+	"strings"
 )
 
 // MistralConfig defines the configuration for Mistral models
@@ -117,7 +118,7 @@ func (c *MistralConfig) GetArchitecture() string {
 	if len(c.Architectures) > 0 {
 		return c.Architectures[0]
 	}
-	return "MistralModel"
+	return ""
 }
 
 func (c *MistralConfig) GetModelType() string {
@@ -140,9 +141,10 @@ func (c *MistralConfig) HasVision() bool {
 	return false
 }
 
-// IsEmbedding returns true since this is an embedding model
+// IsEmbedding returns true when the architecture is "MistralModel", which indicates
+// an embedding model (e.g. intfloat/e5-mistral-7b-instruct).
 func (c *MistralConfig) IsEmbedding() bool {
-	return true
+	return strings.EqualFold(c.GetArchitecture(), "MistralModel")
 }
 
 // Register the Mistral model handler

pkg/hfutil/modelconfig/mistral_test.go

@@ -84,6 +84,65 @@ func TestLoadModelWithMistral(t *testing.T) {
 	t.Logf("Mistral model parameter count via generic loader: %s", FormatParamCount(paramCount))
 }
 
+// TestMistralConfigNoArchitectures verifies that when the Architectures field
+// is missing from config.json, GetArchitecture() returns an empty string rather
+// than a misleading fallback like "MistralModel" which would cause the model to
+// be misclassified as an embedding model by the config parser.
+// Regression test for https://github.com/ome-projects/ome/issues/601
+func TestMistralConfigNoArchitectures(t *testing.T) {
+	configPath := filepath.Join("testdata", "mistral_no_architectures.json")
+
+	config, err := LoadModelConfig(configPath)
+	if err != nil {
+		t.Fatalf("Failed to load Mistral config without architectures: %v", err)
+	}
+
+	// GetArchitecture must return empty string when Architectures is absent
+	arch := config.GetArchitecture()
+	if arch != "" {
+		t.Errorf("Expected empty architecture when Architectures field is missing, got '%s'", arch)
+	}
+
+	// IsEmbedding must return false for a generic Mistral model
+	if config.IsEmbedding() {
+		t.Error("Expected IsEmbedding() to return false for a generic Mistral model without explicit embedding architecture")
+	}
+
+	// Verify it's still recognized as a Mistral model
+	if config.GetModelType() != "mistral" {
+		t.Errorf("Expected model type 'mistral', got '%s'", config.GetModelType())
+	}
+}
+
+// TestMistralConfigEmbedding verifies that a Mistral model with
+// "architectures": ["MistralModel"] is correctly identified as an embedding
+// model (e.g. intfloat/e5-mistral-7b-instruct).
+// This is the load-bearing positive case for config_parser.go's EMBEDDING classification.
+func TestMistralConfigEmbedding(t *testing.T) {
+	configPath := filepath.Join("testdata", "mistral_embedding.json")
+
+	config, err := LoadModelConfig(configPath)
+	if err != nil {
+		t.Fatalf("Failed to load Mistral embedding config: %v", err)
+	}
+
+	// GetArchitecture must return "MistralModel"
+	arch := config.GetArchitecture()
+	if arch != "MistralModel" {
+		t.Errorf("Expected architecture 'MistralModel', got '%s'", arch)
+	}
+
+	// GetModelType must return "mistral"
+	if config.GetModelType() != "mistral" {
+		t.Errorf("Expected model type 'mistral', got '%s'", config.GetModelType())
+	}
+
+	// IsEmbedding must return true for MistralModel architecture
+	if !config.IsEmbedding() {
+		t.Error("Expected IsEmbedding() to return true for a model with 'MistralModel' architecture")
+	}
+}
+
 func TestMistralInstructConfig(t *testing.T) {
 	configPath := filepath.Join("testdata", "mistral_7b_instruct.json")
 

pkg/hfutil/modelconfig/testdata/mistral_embedding.json

@@ -0,0 +1,22 @@
+{
+  "architectures": ["MistralModel"],
+  "bos_token_id": 1,
+  "eos_token_id": 2,
+  "hidden_act": "silu",
+  "hidden_size": 4096,
+  "initializer_range": 0.02,
+  "intermediate_size": 14336,
+  "max_position_embeddings": 32768,
+  "model_type": "mistral",
+  "num_attention_heads": 32,
+  "num_hidden_layers": 32,
+  "num_key_value_heads": 8,
+  "rms_norm_eps": 1e-05,
+  "rope_theta": 10000.0,
+  "sliding_window": 4096,
+  "tie_word_embeddings": false,
+  "torch_dtype": "float16",
+  "transformers_version": "4.36.0",
+  "use_cache": true,
+  "vocab_size": 32000
+}

pkg/hfutil/modelconfig/testdata/mistral_no_architectures.json

@@ -0,0 +1,21 @@
+{
+  "bos_token_id": 1,
+  "eos_token_id": 2,
+  "hidden_act": "silu",
+  "hidden_size": 4096,
+  "initializer_range": 0.02,
+  "intermediate_size": 14336,
+  "max_position_embeddings": 32768,
+  "model_type": "mistral",
+  "num_attention_heads": 32,
+  "num_hidden_layers": 32,
+  "num_key_value_heads": 8,
+  "rms_norm_eps": 1e-05,
+  "rope_theta": 10000.0,
+  "sliding_window": 4096,
+  "tie_word_embeddings": false,
+  "torch_dtype": "bfloat16",
+  "transformers_version": "4.34.0.dev0",
+  "use_cache": true,
+  "vocab_size": 32000
+}