test: add and update tests

---
type: pre_commit_static_analysis_report
description: Results of running static analysis checks when committing changes.
report:
  - task: lint_filenames
    status: passed
  - task: lint_editorconfig
    status: passed
  - task: lint_markdown
    status: na
  - task: lint_package_json
    status: na
  - task: lint_repl_help
    status: na
  - task: lint_javascript_src
    status: passed
  - task: lint_javascript_cli
    status: na
  - task: lint_javascript_examples
    status: na
  - task: lint_javascript_tests
    status: passed
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  - task: lint_python
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  - task: lint_r
    status: na
  - task: lint_c_src
    status: na
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    status: na
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    status: na
  - task: lint_c_tests_fixtures
    status: na
  - task: lint_shell
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  - task: lint_typescript_declarations
    status: na
  - task: lint_typescript_tests
    status: na
  - task: lint_license_headers
    status: passed
---

Author: kgryte

lib/node_modules/@stdlib/ndarray/flatten/lib/main.js

@@ -51,7 +51,7 @@ var COL_MAJOR = 'column-major';
 * Returns a flattened copy of an input ndarray.
 *
 * @param {ndarray} x - input ndarray
-* @param {Object} [options] - function options
+* @param {Options} [options] - function options
 * @param {NonNegativeInteger} [options.depth] - maximum number of dimensions to flatten
 * @param {string} [options.order='row-major'] - order in which input ndarray elements should be flattened
 * @throws {TypeError} first argument must be an ndarray-like object
@@ -284,6 +284,7 @@ function flatten( x, options ) {
 	var view;
 	var opts;
 	var xsh;
+	var st;
 	var o;
 	var y;
 
@@ -342,7 +343,8 @@ function flatten( x, options ) {
 	});
 
 	// Create a view on top of output ndarray having the same shape as the input ndarray:
-	view = ndarray( getDType( y ), getData( y ), xsh, shape2strides( xsh, opts.order ), 0, opts.order ); // eslint-disable-line max-len
+	st = ( xsh.length > 0 ) ? shape2strides( xsh, opts.order ) : [ 0 ];
+	view = ndarray( getDType( y ), getData( y ), xsh, st, 0, opts.order );
 
 	// Copy elements to the output ndarray:
 	assign( [ x, view ] );