function onStringLiteral( path ) {
		if ( path.value.value === '@stdlib/string-format' ) {
			debug( 'Replacing `@stdlib/string-format` with `@stdlib/error-tools-fmtprodmsg`...' );
			j( path )
				.replaceWith( j.stringLiteral( '@stdlib/error-tools-fmtprodmsg' ) );
		}
		// If the string literal is inside a NewExpression for an error, replace the string literal with the error message...
		else if (
			// Case: new Error( format( '...', ... ) )
			path.parent.parent.value.type === 'NewExpression' &&
			ERROR_NAMES.indexOf( path.parent.parent.value.callee.name ) !== -1
		) {
			id = msg2id( path.value.value );
			if ( id ) {
				code = prefix + id;
				debug( 'Replacing format string "'+path.value.value+'" with error code "'+code+'"...' );
				j( path )
					.replaceWith( j.stringLiteral( code ) );
			}
		}
		else if (
			// Case: new Error( '...' )
			path.parent.value.type === 'NewExpression' &&
			ERROR_NAMES.indexof( path.parent.value.callee.name ) !== -1
		) {
			id = msg2id( path.value.value );
			if ( id ) {
				code = prefix + id;
				debug( 'Replacing string literal "'+path.value.value+'" with error code "'+code+'"...' );

				// Replace with call to `format` with the error code...
				replacement = j.callExpression(j.identifier( formatVar ), [
					j.stringLiteral( code )
				]);
				j( path ).replaceWith( replacement );

				// Add `require` call to `@stdlib/error-tools-fmtprodmsg` if not already present...
				nRequires = requires.size();
				debug( 'Found ' + nRequires + ' `require` calls...' );
				if ( !requires.some( hasRequire ) ) {
					formatRequire = j.variableDeclaration('var', [
						j.variableDeclarator(j.identifier( formatVar ), j.callExpression(j.identifier( 'require' ), [
							j.stringLiteral( '@stdlib/error-tools-fmtprodmsg' )
						]))
					]);
					debug( 'Adding `require` call to `@stdlib/error-tools-fmtprodmsg`...' );
					j( root.find( j.Declaration ).at( 0 ).get() ).insertBefore( formatRequire );
				}
			}
		}
	}
Callback invoked upon finding a string literal.

@private
@param {Object} path - AST node path
@returns {void}