build: ensure dir is initialized before checking relative paths

---
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
  - 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

lib/node_modules/@stdlib/_tools/eslint/rules/require-file-extensions/lib/main.js

@@ -112,6 +112,8 @@ function main( context ) {
 		if ( node.callee.name === 'require' ) {
 			requirePath = node.arguments[ 0 ].value;
 			if ( isString( requirePath ) ) {
+				filename = context.getFilename();
+				dir = dirname( filename );
 				if ( startsWith( requirePath, '.' ) ) {
 					requirePath = path.resolve( dir, requirePath );
 				}
@@ -128,8 +130,6 @@ function main( context ) {
 						}
 					}
 				}
-				filename = context.getFilename();
-				dir = dirname( filename );
 				resolved = tryResolve( requirePath, dir );
 				parts = path.parse( requirePath );
 

lib/node_modules/@stdlib/_tools/eslint/rules/require-file-extensions/test/fixtures/valid.js

@@ -21,6 +21,13 @@
 // MODULES //
 
 var resolve = require( 'path' ).resolve;
+var join = require( 'path' ).join;
+var rootDir = require( '@stdlib/_tools/utils/root-dir' );
+
+
+// VARIABLES //
+
+var ROOT_DIR = rootDir();
 
 
 // MAIN //
@@ -106,6 +113,16 @@ test = {
 };
 valid.push( test );
 
+test = {
+	'code': [
+		'// MODULES //',
+		'',
+		'var main = require( \'./main.js\' );'
+	].join( '\n' ),
+	'filename': join( ROOT_DIR, 'lib/index.js' )
+};
+valid.push( test );
+
 
 // EXPORTS //