Added: docs for GetFile use case

docs/useCases.md

@@ -20,6 +20,7 @@ The different use cases currently available in the package are classified below,
     - [List All Datasets](#list-all-datasets)
 - [Files](#Files)
   - [Files read use cases](#files-read-use-cases)
+    - [Get a File](#get-a-file)
     - [Get File Counts in a Dataset](#get-file-counts-in-a-dataset)
     - [Get File Data Tables](#get-file-data-tables)
     - [Get File Download Count](#get-file-download-count)
@@ -238,6 +239,33 @@ The `DatasetPreviewSubset`returned instance contains a property called `totalDat
 
 ### Files read use cases
 
+#### Get a File
+
+Returns a [File](../src/files/domain/models/Dataset.ts) instance, given the search parameters to identify it.
+
+##### Example call:
+
+```typescript
+import { getFile } from '@iqss/dataverse-client-javascript';
+
+/* ... */
+
+const fileId = 2;
+const datasetVersionId = '1.0';
+
+getFile.execute(fileId, datasetVersionId).then((file: File) => {
+  /* ... */
+});
+
+/* ... */
+```
+
+_See [use case](../src/files/domain/useCases/GetFile.ts)_ definition.
+
+The `fileId` parameter can be a string, for persistent identifiers, or a number, for numeric identifiers.
+
+The `datasetVersionId` parameter can correspond to a numeric version identifier, as in the previous example, or a [DatasetNotNumberedVersion](../src/datasets/domain/models/DatasetNotNumberedVersion.ts) enum value. If not set, the default value is `DatasetNotNumberedVersion.LATEST`.
+
 #### Get File Counts in a Dataset
 
 Returns an instance of [FileCounts](../src/files/domain/models/FileCounts.ts), containing the requested Dataset total file count, as well as file counts for the following file properties:

src/files/domain/useCases/GetFile.ts

@@ -5,6 +5,13 @@ import { DatasetNotNumberedVersion } from '../../../datasets';
 export class GetFile {
   constructor(private readonly filesRepository: IFilesRepository) {}
 
+  /**
+   * Returns a File instance, given the search parameters to identify it.
+   *
+   * @param {number | string} [fileId] - The File identifier, which can be a string (for persistent identifiers), or a number (for numeric identifiers).
+   * @param {string | DatasetNotNumberedVersion} [datasetVersionId=DatasetNotNumberedVersion.LATEST] - The dataset version identifier, which can be a version-specific numeric string (for example, 1.0) or a DatasetNotNumberedVersion enum value. If this parameter is not set, the default value is: DatasetNotNumberedVersion.LATEST
+   * @returns {Promise<File>}
+   */
   async execute(
     fileId: number | string,
     datasetVersionId: string | DatasetNotNumberedVersion = DatasetNotNumberedVersion.LATEST,