build: add format-args ESLint rule

etc/eslint/rules/stdlib.js

@@ -1,4 +1,4 @@
-/* eslint-disable stdlib/jsdoc-doctest-marker, stdlib/jsdoc-doctest, stdlib/jsdoc-example-require-spacing, stdlib/jsdoc-no-tabs */
+/* eslint-disable stdlib/jsdoc-doctest-marker, stdlib/jsdoc-example-require-spacing, stdlib/jsdoc-no-tabs */
 
 /**
 * @license Apache-2.0
@@ -275,6 +275,28 @@
 */
 rules[ 'stdlib/eol-open-bracket-spacing' ] = 'error';
 
+/**
+* Require that format calls are provided an expected number of arguments.
+*
+* @name format-args
+* @memberof rules
+* @type {string}
+* @default 'error'
+*
+* @example
+* // Bad...
+* var format = require( '@stdlib/string/format' );
+*
+* var str = format( '%s %s', 'foo' );
+*
+* @example
+* // Good...
+* var format = require( '@stdlib/string/format' );
+*
+* var str = format( '%s %s', 'foo', 'bar' );
+*/
+rules[ 'stdlib/format-args' ] = 'error';
+
 /**
 * Require blockquotes to have `2` character indentation.
 *
@@ -879,7 +901,7 @@
 * // Bad...
 *
 * /**
 * * Fréchet distribution constructor.
 * *
 * * @module @stdlib/stats/base/dists/frechet/ctor
 * *
@@ -895,7 +917,7 @@
 * // Good...
 *
 * /**
 * * Fréchet distribution constructor.
 * *
 * * @module @stdlib/stats/base/dists/frechet/ctor
 * *

lib/node_modules/@stdlib/_tools/eslint/rules/format-args/README.md

@@ -0,0 +1,140 @@
+<!--
+
+@license Apache-2.0
+
+Copyright (c) 2026 The Stdlib Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+-->
+
+# format-args
+
+> [ESLint rule][eslint-rules] requiring that format calls are provided an expected number of arguments.
+
+<section class="intro">
+
+</section>
+
+<!-- /.intro -->
+
+<section class="usage">
+
+## Usage
+
+```javascript
+var rule = require( '@stdlib/_tools/eslint/rules/format-args' );
+```
+
+#### rule
+
+[ESLint rule][eslint-rules] requiring that calls to the format function exported by [`@stdlib/string/format`][@stdlib/string/format] are provided a number of arguments matching the number of placeholders in the format string.
+
+**Bad**:
+
+<!-- eslint-disable stdlib/format-args -->
+
+```javascript
+var format = require( '@stdlib/string/format' );
+
+var str = format( '%s %s', 'foo' );
+```
+
+**Good**:
+
+```javascript
+var format = require( '@stdlib/string/format' );
+
+var str = format( '%s %s', 'foo', 'bar' );
+// returns 'foo bar'
+```
+
+</section>
+
+<!-- /.usage -->
+
+<section class="notes">
+
+## Notes
+
+-   The rule only applies when the format function is resolved from a `require( '@stdlib/string/format' )` statement, thus guarding against unrelated symbols sharing the same name and against shadowed symbols.
+-   The rule skips calls in which the format string is not a string literal, calls containing spread elements, calls via `#.call` and `#.apply`, and format strings containing positional placeholders (e.g., `%1$s`).
+
+</section>
+
+<!-- /.notes -->
+
+<section class="examples">
+
+## Examples
+
+<!-- eslint no-undef: "error" -->
+
+```javascript
+var Linter = require( 'eslint' ).Linter;
+var rule = require( '@stdlib/_tools/eslint/rules/format-args' );
+
+var linter = new Linter();
+
+var code = [
+    'var format = require( \'@stdlib/string/format\' );',
+    '',
+    'var str = format( \'%s %s\', \'foo\' );'
+].join( '\n' );
+
+linter.defineRule( 'format-args', rule );
+
+var result = linter.verify( code, {
+    'rules': {
+        'format-args': 'error'
+    }
+});
+/* returns
+    [
+        {
+            'ruleId': 'format-args',
+            'severity': 2,
+            'message': 'Unexpected number of format arguments. Format string expects 2 argument(s), but 1 argument(s) were provided.',
+            'line': 3,
+            'column': 11,
+            'nodeType': 'CallExpression',
+            'endLine': 3,
+            'endColumn': 35
+        }
+    ]
+*/
+```
+
+</section>
+
+<!-- /.examples -->
+
+<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->
+
+<section class="related">
+
+</section>
+
+<!-- /.related -->
+
+<!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->
+
+<section class="links">
+
+[eslint-rules]: https://eslint.org/docs/developer-guide/working-with-rules
+
+[@stdlib/string/format]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/string/format
+
+</section>
+
+<!-- /.links -->

lib/node_modules/@stdlib/_tools/eslint/rules/format-args/examples/index.js

@@ -0,0 +1,52 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2026 The Stdlib Authors.
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+*    http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+'use strict';
+
+var Linter = require( 'eslint' ).Linter;
+var rule = require( './../lib' );
+
+var linter = new Linter();
+var code = [
+	'var format = require( \'@stdlib/string/format\' );',
+	'',
+	'var str = format( \'%s %s\', \'foo\' );'
+].join( '\n' );
+
+linter.defineRule( 'format-args', rule );
+
+var results = linter.verify( code, {
+	'rules': {
+		'format-args': 'error'
+	}
+});
+console.log( results );
+/* =>
+	[
+		{
+			'ruleId': 'format-args',
+			'severity': 2,
+			'message': 'Unexpected number of format arguments. Format string expects 2 argument(s), but 1 argument(s) were provided.',
+			'line': 3,
+			'column': 11,
+			'nodeType': 'CallExpression',
+			'endLine': 3,
+			'endColumn': 35
+		}
+	]
+*/

lib/node_modules/@stdlib/_tools/eslint/rules/format-args/lib/index.js

@@ -0,0 +1,39 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2026 The Stdlib Authors.
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+*    http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+'use strict';
+
+/**
+* ESLint rule requiring that format calls are provided an expected number of arguments.
+*
+* @module @stdlib/_tools/eslint/rules/format-args
+*
+* @example
+* var rule = require( '@stdlib/_tools/eslint/rules/format-args' );
+*
+* console.log( rule );
+*/
+
+// MODULES //
+
+var main = require( './main.js' );
+
+
+// EXPORTS //
+
+module.exports = main;