Handle form validation

web/e2e/specs/settings/detection-models.spec.ts

@@ -286,6 +286,42 @@ test.describe("Detection models settings @high", () => {
     ).toBeDisabled();
   });
 
+  test("two models without a path share the detector's default model", async ({
+    frigateApp,
+  }) => {
+    await installRoutes(frigateApp.page, [
+      { scene: "default", devices: ["cpu"] },
+      { scene: "driveway", devices: ["cpu"] },
+    ]);
+    await openPage(frigateApp);
+
+    await expect(frigateApp.page.locator("#pageRoot")).toContainText(
+      "The Default and driveway models use the same model file",
+    );
+  });
+
+  test("another spelling of the same path is the same model", async ({
+    frigateApp,
+  }) => {
+    await installRoutes(frigateApp.page, [
+      {
+        scene: "default",
+        devices: ["openvino:GPU.0"],
+        path: "/config/model_cache/yolo.onnx",
+      },
+      {
+        scene: "driveway",
+        devices: ["openvino:GPU.1"],
+        path: "/config//model_cache/./tmp/../yolo.onnx",
+      },
+    ]);
+    await openPage(frigateApp);
+
+    await expect(frigateApp.page.locator("#pageRoot")).toContainText(
+      "The Default and driveway models use the same model file",
+    );
+  });
+
   test("one model file may run on different detectors", async ({
     frigateApp,
   }) => {

web/src/components/config-form/section-validations/models.ts

@@ -3,6 +3,51 @@ import type { TFunction } from "i18next";
 import { isJsonObject } from "@/lib/utils";
 import { DEFAULT_SCENE, getSceneLabel } from "@/utils/modelUtil";
 
+/** The model the backend loads for a detector when no path is configured. */
+function defaultModelPath(detector: string): string | undefined {
+  if (detector === "cpu" || detector.endsWith("_tfl")) {
+    return "/cpu_model.tflite";
+  }
+
+  if (detector === "edgetpu") {
+    return "/edgetpu_model.tflite";
+  }
+
+  if (detector === "openvino") {
+    return "/openvino-model/ssdlite_mobilenet_v2.xml";
+  }
+
+  return undefined;
+}
+
+/**
+ * Collapse `//`, `.`, and `..` so spellings of one file path compare equal,
+ * as the backend's realpath does. Symlinks and copies can only be seen by the
+ * backend, which still combines them at startup.
+ */
+function normalizeModelPath(path: string): string {
+  // plus://<id> and other URLs are compared as written
+  if (path.includes("://")) {
+    return path;
+  }
+
+  const segments: string[] = [];
+
+  for (const segment of path.split("/")) {
+    if (segment === "" || segment === ".") {
+      continue;
+    }
+
+    if (segment === ".." && segments.length && segments.at(-1) !== "..") {
+      segments.pop();
+    } else if (segment !== ".." || !path.startsWith("/")) {
+      segments.push(segment);
+    }
+  }
+
+  return `${path.startsWith("/") ? "/" : ""}${segments.join("/")}`;
+}
+
 /**
  * A camera that names no scene runs the model whose scene is `default`.
  * Without one the backend rejects the config outright once a second model
@@ -38,14 +83,23 @@ export function validateModelScenes(
   const seen = new Map<string, string>();
 
   formData.forEach((model, index) => {
-    if (!isJsonObject(model) || typeof model.path !== "string" || !model.path) {
+    if (!isJsonObject(model)) {
       return;
     }
 
     const devices = Array.isArray(model.devices) ? model.devices : [];
     const detector =
       typeof devices[0] === "string" ? devices[0].split(":")[0] : "";
-    const key = `${detector}|${model.path}`;
+    const path =
+      typeof model.path === "string" && model.path
+        ? normalizeModelPath(model.path)
+        : defaultModelPath(detector);
+
+    if (!path) {
+      return;
+    }
+
+    const key = `${detector}|${path}`;
     const other = seen.get(key);
 
     if (other === undefined) {