refactor: apply suggestions from code review

---
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: passed
  - task: lint_javascript_tests
    status: passed
  - task: lint_javascript_benchmarks
    status: na
  - task: lint_python
    status: na
  - task: lint_r
    status: na
  - task: lint_c_src
    status: na
  - task: lint_c_examples
    status: na
  - task: lint_c_benchmarks
    status: na
  - task: lint_c_tests_fixtures
    status: na
  - task: lint_shell
    status: na
  - task: lint_typescript_declarations
    status: na
  - task: lint_typescript_tests
    status: na
  - task: lint_license_headers
    status: passed
---

Author: headlessNode

lib/node_modules/@stdlib/ndarray/flatten-by/examples/index.js

@@ -24,7 +24,7 @@ var ndarray2array = require( '@stdlib/ndarray/to-array' );
 var flattenBy = require( './../lib' );
 
 function scale( value ) {
-    return value * 2.0;
+	return value * 2.0;
 }
 
 var xbuf = discreteUniform( 12, -100, 100, {

lib/node_modules/@stdlib/ndarray/flatten-by/lib/index.js

@@ -36,8 +36,7 @@
 * var x = array( [ [ [ 1.0, 2.0 ] ], [ [ 3.0, 4.0 ] ], [ [ 5.0, 6.0 ] ] ] );
 * // return <ndarray>
 *
-* // Flatten the input ndarray:
-* var y = flatten( x, scale );
+* var y = flattenBy( x, scale );
 * // returns <ndarray>
 *
 * var arr = ndarray2array( y );

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

@@ -21,20 +21,8 @@
 // MODULES //
 
 var isPlainObject = require( '@stdlib/assert/is-plain-object' );
-var hasOwnProp = require( '@stdlib/assert/has-own-property' );
+var isFunction = require( '@stdlib/assert/is-function' );
 var isndarrayLike = require( '@stdlib/assert/is-ndarray-like' );
-var isNonNegativeInteger = require( '@stdlib/assert/is-nonnegative-integer' );
-var isOrder = require( '@stdlib/ndarray/base/assert/is-order' );
-var getShape = require( '@stdlib/ndarray/shape' );
-var getOrder = require( '@stdlib/ndarray/order' );
-var getStrides = require( '@stdlib/ndarray/strides' );
-var getData = require( '@stdlib/ndarray/base/data-buffer' );
-var getDType = require( '@stdlib/ndarray/base/dtype' );
-var shape2strides = require( '@stdlib/ndarray/base/shape2strides' );
-var strides2order = require( '@stdlib/ndarray/base/strides2order' );
-var flattenShape = require( '@stdlib/ndarray/base/flatten-shape' );
-var assign = require( '@stdlib/ndarray/base/assign' );
-var emptyLike = require( '@stdlib/ndarray/empty-like' );
 var map = require( '@stdlib/ndarray/map' );
 var flatten = require( '@stdlib/ndarray/flatten' );
 var format = require( '@stdlib/string/format' );
@@ -80,35 +68,35 @@ function flattenBy( x, options, fcn, thisArg ) {
 	var cb;
 	var y;
 
-    if ( !isndarrayLike( x ) ) {
+	if ( !isndarrayLike( x ) ) {
 		throw new TypeError( format( 'invalid argument. First argument must be an ndarray-like object. Value: `%s`.', x ) );
 	}
-    opts = {};
+	opts = {};
 	if ( arguments.length < 3 ) { // Case: flattenBy( x, fcn )
 		cb = options;
 	} else if ( arguments.length === 3 ) {
 		if ( isFunction( options ) ) { // Case: flattenBy( x, fcn, thisArg )
 			cb = options;
 			ctx = fcn;
 		} else { // Case: flattenBy( x, options, fcn )
-            if ( !isPlainObject( options ) ) {
-                throw new TypeError( format( 'invalid argument. Options argument must be an object. Value: `%s`.', options ) );
-            }
+			if ( !isPlainObject( options ) ) {
+				throw new TypeError( format( 'invalid argument. Options argument must be an object. Value: `%s`.', options ) );
+			}
 			opts = options;
 			cb = fcn;
 		}
 	} else {
-        if ( !isPlainObject( options ) ) {
-            throw new TypeError( format( 'invalid argument. Options argument must be an object. Value: `%s`.', options ) );
-        }
+		if ( !isPlainObject( options ) ) {
+			throw new TypeError( format( 'invalid argument. Options argument must be an object. Value: `%s`.', options ) );
+		}
 		opts = options;
 		cb = fcn;
 		ctx = thisArg;
 	}
 	if ( !isFunction( cb ) ) {
 		throw new TypeError( format( 'invalid argument. Callback argument must be a function. Value: `%s`.', cb ) );
 	}
-    y = map( x, cb, ctx );
+	y = map( x, cb, ctx );
 	return flatten( y, opts );
 }