chore: address PR review feedback

---
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: passed
  - 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: na
  - 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: Planeshifter

.github/workflows/generate_monthly_changelog.yml

@@ -105,13 +105,14 @@ jobs:
           var generate = require( '@stdlib/_tools/changelog/generate' );
           var changelog = generate( '@stdlib', {
             'flags': {
-              'since': '$UNTIL - 1 week',
+              'since': '$UNTIL - 1 month',
               'until': '$UNTIL'
             },
             'format': 'aggregated'
           });
           console.log( changelog.content );
-          " > ./www-blog-monthly-changelog/monthly_changelog_$UNTIL.md
+
+          " > ./www-blog-monthly-changelog/monthly_changelog_${UNTIL//-/_}.md
 
       # Import GPG key to sign commits:
       - name: 'Import GPG key to sign commits'

lib/node_modules/@stdlib/_tools/changelog/generate/README.md

@@ -47,10 +47,12 @@ The function returns an object with the following properties:
 The function accepts the following `options`:
 
 -   **releaseType**: a release type for which to generate the changelog.
+
 -   **format**: changelog format. Must be one of the following:
 
     -   `'grouped'`: group commits by package.
     -   `'aggregated'`: TODO:add description.
+
 -   **flags**: `git log` options used to retrieve commits from which to generate the changelog.
 
 By default, the changelog is generated for a non-release. To generate a changelog for an upcoming release, provide a valid release type:
@@ -97,12 +99,12 @@ changelog = generate( '@stdlib/math/base/utils', {
 
 When generating a changelog, the function uses `git log` to retrieve the commits from which to assemble a set of changes. The `flags` option allows passing options to directly to the `git log` command (e.g., to generate a changelog for a specified time interval or for an individual contributor).
 
-<!-- eslint-disable stdlib/doctest -->
+<!-- eslint-disable -->
 
 ```javascript
 var changelog = generate( '@stdlib/ndarray', {
     'flags': {
-        'since': 'last month'
+        'since': 'last year'
     }
 });
 // returns {...}
@@ -121,8 +123,6 @@ changelog = generate( '@stdlib/ndarray', {
 
 <section class="notes">
 
--   When `flags` are supplied, the generated changelog does not include empty releases and uses a flat output format.
-
 </section>
 
 <!-- /.notes -->

lib/node_modules/@stdlib/_tools/changelog/generate/lib/validate.js

@@ -24,13 +24,14 @@ var isObject = require( '@stdlib/assert/is-plain-object' );
 var hasOwnProp = require( '@stdlib/assert/has-own-property' );
 var isString = require( '@stdlib/assert/is-string' ).isPrimitive;
 var isPlainObject = require( '@stdlib/assert/is-plain-object' );
-var indexOf = require( '@stdlib/utils/index-of' );
+var contains = require( '@stdlib/array/base/assert/contains' ).factory;
 var format = require( '@stdlib/string/format' );
 
 
 // VARIABLES //
 
 var FORMAT_OPTIONS = [ 'grouped', 'aggregated' ];
+var isFormat = contains( FORMAT_OPTIONS );
 
 
 // MAIN //
@@ -42,7 +43,7 @@ var FORMAT_OPTIONS = [ 'grouped', 'aggregated' ];
 * @param {Object} opts - destination for function options
 * @param {Options} options - function options
 * @param {string} [options.releaseType] - release type
-* @param {string} [options.format] - output format (`grouped` or `aggregated`)
+* @param {string} [options.format] - output format
 * @param {string} [options.flags] - `git log` options used to retrieve commits
 * @returns {(Error|null)} error or null
 *
@@ -68,7 +69,7 @@ function validate( opts, options ) {
 	}
 	if ( hasOwnProp( options, 'format' ) ) {
 		opts.format = options.format;
-		if ( indexOf( FORMAT_OPTIONS, opts.format ) === -1 ) {
+		if ( !isFormat( opts.format ) ) {
 			return new TypeError( format( 'invalid option. `%s` option must be one of the following: "%s". Option: `%s`.', 'format', FORMAT_OPTIONS.join( '", "' ), opts.format ) );
 		}
 	}