Extend analyze command to provide subtree information

src/base/contentTypes/FileExtensions.ts

@@ -0,0 +1,63 @@
+import { ContentDataTypeRegistry } from "./ContentDataTypeRegistry";
+import { ContentDataTypes } from "./ContentDataTypes";
+
+/**
+ * Methods related to file extensions for the content data types
+ * that are defined in `ContentDataTypes`
+ */
+export class FileExtensions {
+  /**
+   * A dictionary of the content data types to the default
+   * file extensions (without dot)
+   */
+  private static readonly knownFileExtensionsWithoutDot = {
+    [ContentDataTypes.CONTENT_TYPE_GLB]: "glb",
+    [ContentDataTypes.CONTENT_TYPE_B3DM]: "b3dm",
+    [ContentDataTypes.CONTENT_TYPE_I3DM]: "i3dm",
+    [ContentDataTypes.CONTENT_TYPE_CMPT]: "cmpt",
+    [ContentDataTypes.CONTENT_TYPE_PNTS]: "pnts",
+    [ContentDataTypes.CONTENT_TYPE_GEOM]: "geom",
+    [ContentDataTypes.CONTENT_TYPE_VCTR]: "vctr",
+    [ContentDataTypes.CONTENT_TYPE_SUBT]: "subt",
+    [ContentDataTypes.CONTENT_TYPE_PNG]: "png",
+    [ContentDataTypes.CONTENT_TYPE_JPEG]: "jpg",
+    [ContentDataTypes.CONTENT_TYPE_GIF]: "gif",
+    [ContentDataTypes.CONTENT_TYPE_GEOJSON]: "geojson",
+    [ContentDataTypes.CONTENT_TYPE_3TZ]: "3tz",
+    [ContentDataTypes.CONTENT_TYPE_GLTF]: "gltf",
+    [ContentDataTypes.CONTENT_TYPE_TILESET]: "json",
+  };
+
+  /**
+   * Returns the default extension (without dot) for files with the given
+   * content data type. If the given content data type is undefined or
+   * not known, then an empty string will be returned.
+   *
+   * @param type - The `ContentDataType`
+   * @returns The file extension
+   */
+  static getDefaultFileExtension(type: string | undefined): string {
+    if (type === undefined) {
+      return "";
+    }
+    const result = FileExtensions.knownFileExtensionsWithoutDot[type];
+    if (result === undefined) {
+      return "";
+    }
+    return result;
+  }
+
+  /**
+   * Returns the default extension (without dot) for the given file
+   * data, depending on its content type. If the content data type
+   * cannot be determined or is not known, then an empty string will
+   * be returned.
+   *
+   * @param data - The file data
+   * @returns A promise to the file extension
+   */
+  static async determineFileExtension(data: Buffer): Promise<string> {
+    const type = await ContentDataTypeRegistry.findType("", data);
+    return FileExtensions.getDefaultFileExtension(type);
+  }
+}

src/base/index.ts

@@ -20,6 +20,7 @@ export * from "./contentTypes/ContentDataTypeEntry";
 export * from "./contentTypes/ContentDataTypeRegistry";
 export * from "./contentTypes/ContentDataTypes";
 export * from "./contentTypes/LazyContentData";
+export * from "./contentTypes/FileExtensions";
 
 export * from "./io/FileResourceResolver";
 export * from "./io/ResourceResolver";