feat: add no-unnecessary-format 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
@@ -901,7 +901,7 @@
 * *
 * * @example
 * * var Frechet = require( '@stdlib/stats/base/dists/frechet/ctor' );
 * *
 * * var frechet = new Frechet( 1.0, 1.0, 0.5 );
 * *
 * * var y = frechet.cdf( 0.8 );
@@ -917,7 +917,7 @@
 * @memberof rules
 * @type {Array}
 * @default [ 'error', '`' ]
 * @see [fenced-code-marker]{@link https://github.com/wooorm/remark-lint/tree/master/packages/remark-lint-fenced-code-marker}
 *
 * @example
 * // Bad...
@@ -4442,6 +4442,26 @@
 */
 rules[ 'stdlib/no-unnecessary-nested-functions' ] = 'error';
 
+/**
+* Disallow format calls that do not perform string interpolation.
+*
+* @name no-unnecessary-format
+* @memberof rules
+* @type {string}
+* @default 'error'
+*
+* @example
+* // Bad...
+* var format = require( '@stdlib/string/format' );
+*
+* throw new Error( format( 'invalid argument.' ) );
+*
+* @example
+* // Good...
+* throw new Error( 'invalid argument.' );
+*/
+rules[ 'stdlib/no-unnecessary-format' ] = 'error';
+
 /**
 * Disallow the use of the `new Array()` constructor.
 *

lib/node_modules/@stdlib/_tools/eslint/rules/lib/index.js

@@ -1017,6 +1017,15 @@ setReadOnly( rules, 'no-single-property-require', require( '@stdlib/_tools/eslin
 */
 setReadOnly( rules, 'no-unassigned-require', require( '@stdlib/_tools/eslint/rules/no-unassigned-require' ) );
 
+/**
+* @name no-unnecessary-format
+* @memberof rules
+* @readonly
+* @type {Function}
+* @see {@link module:@stdlib/_tools/eslint/rules/no-unnecessary-format}
+*/
+setReadOnly( rules, 'no-unnecessary-format', require( '@stdlib/_tools/eslint/rules/no-unnecessary-format' ) );
+
 /**
 * @name no-unnecessary-nested-functions
 * @memberof rules

lib/node_modules/@stdlib/_tools/eslint/rules/no-unnecessary-format/README.md

@@ -0,0 +1,136 @@
+<!--
+
+@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.
+
+-->
+
+# no-unnecessary-format
+
+> [ESLint rule][eslint-rules] disallowing format calls that do not perform string interpolation.
+
+<section class="intro">
+
+</section>
+
+<!-- /.intro -->
+
+<section class="usage">
+
+## Usage
+
+```javascript
+var rule = require( '@stdlib/_tools/eslint/rules/no-unnecessary-format' );
+```
+
+#### rule
+
+[ESLint rule][eslint-rules] disallowing calls to the format function exported by [`@stdlib/string/format`][@stdlib/string/format] when the format string does not contain any placeholders. Such calls are unnecessary, as the format function simply returns the input string unchanged.
+
+**Bad**:
+
+<!-- run-disable -->
+
+<!-- eslint-disable stdlib/no-unnecessary-format -->
+
+```javascript
+var format = require( '@stdlib/string/format' );
+
+throw new Error( format( 'invalid argument.' ) );
+```
+
+**Good**:
+
+<!-- run-disable -->
+
+```javascript
+throw new Error( 'invalid argument.' );
+```
+
+</section>
+
+<!-- /.usage -->
+
+<section class="notes">
+
+</section>
+
+<!-- /.notes -->
+
+<section class="examples">
+
+## Examples
+
+<!-- eslint no-undef: "error" -->
+
+```javascript
+var Linter = require( 'eslint' ).Linter;
+var rule = require( '@stdlib/_tools/eslint/rules/no-unnecessary-format' );
+
+var linter = new Linter();
+
+var code = [
+    'var format = require( \'@stdlib/string/format\' );',
+    '',
+    'throw new Error( format( \'invalid argument.\' ) );'
+].join( '\n' );
+
+linter.defineRule( 'no-unnecessary-format', rule );
+
+var result = linter.verify( code, {
+    'rules': {
+        'no-unnecessary-format': 'error'
+    }
+});
+/* returns
+    [
+        {
+            'ruleId': 'no-unnecessary-format',
+            'severity': 2,
+            'message': 'Unnecessary format call. No placeholders found in format string.',
+            'line': 3,
+            'column': 18,
+            'nodeType': 'CallExpression',
+            'endLine': 3,
+            'endColumn': 47
+        }
+    ]
+*/
+```
+
+</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/no-unnecessary-format/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\' );',
+	'',
+	'throw new Error( format( \'invalid argument.\' ) );'
+].join( '\n' );
+
+linter.defineRule( 'no-unnecessary-format', rule );
+
+var results = linter.verify( code, {
+	'rules': {
+		'no-unnecessary-format': 'error'
+	}
+});
+console.log( results );
+/* =>
+	[
+		{
+			'ruleId': 'no-unnecessary-format',
+			'severity': 2,
+			'message': 'Unnecessary format call. No placeholders found in format string.',
+			'line': 3,
+			'column': 18,
+			'nodeType': 'CallExpression',
+			'endLine': 3,
+			'endColumn': 47
+		}
+	]
+*/

lib/node_modules/@stdlib/_tools/eslint/rules/no-unnecessary-format/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 disallowing format calls that do not perform string interpolation.
+*
+* @module @stdlib/_tools/eslint/rules/no-unnecessary-format
+*
+* @example
+* var rule = require( '@stdlib/_tools/eslint/rules/no-unnecessary-format' );
+*
+* console.log( rule );
+*/
+
+// MODULES //
+
+var main = require( './main.js' );
+
+
+// EXPORTS //
+
+module.exports = main;