[chore]: store regexp as variable instead of defining it inline (#7716)

* store regexp as variable instead of defining it inline

* fix naming of `regex_quoted_value`

* some more variables

* optimize `.replace() calls

* restore formatting changes

* optimize `parser.*` calls

* small refactor

* optimize `.test() calls

* rename some variables

* fix tests

* rename pattern variables

* extract common regexes into `patters.ts`

* rename variables to use snake_case

* fix trim

Author: ivanhofer

src/compiler/compile/Component.ts

@@ -47,6 +47,10 @@ interface ComponentOptions {
 	preserveWhitespace?: boolean;
 }
 
+const regex_leading_directory_separator = /^[/\\]/;
+const regex_starts_with_term_export = /^Export/;
+const regex_contains_term_function = /Function/;
+
 export default class Component {
 	stats: Stats;
 	warnings: Warning[];
@@ -136,7 +140,7 @@ export default class Component {
 			(typeof process !== 'undefined'
 				? compile_options.filename
 					.replace(process.cwd(), '')
-					.replace(/^[/\\]/, '')
+					.replace(regex_leading_directory_separator, '')
 				: compile_options.filename);
 		this.locate = getLocator(this.source, { offsetLine: 1 });
 
@@ -638,7 +642,7 @@ export default class Component {
 				body.splice(i, 1);
 			}
 
-			if (/^Export/.test(node.type)) {
+			if (regex_starts_with_term_export.test(node.type)) {
 				const replacement = this.extract_exports(node, true);
 				if (replacement) {
 					body[i] = replacement;
@@ -795,7 +799,7 @@ export default class Component {
 					return this.skip();
 				}
 
-				if (/^Export/.test(node.type)) {
+				if (regex_starts_with_term_export.test(node.type)) {
 					const replacement = component.extract_exports(node);
 					if (replacement) {
 						this.replace(replacement);
@@ -918,7 +922,7 @@ export default class Component {
 				}
 
 				if (name[1] !== '$' && scope.has(name.slice(1)) && scope.find_owner(name.slice(1)) !== this.instance_scope) {
-					if (!((/Function/.test(parent.type) && prop === 'params') || (parent.type === 'VariableDeclarator' && prop === 'id'))) {
+					if (!((regex_contains_term_function.test(parent.type) && prop === 'params') || (parent.type === 'VariableDeclarator' && prop === 'id'))) {
 						return this.error(node as any, compiler_errors.contextual_store);
 					}
 				}
@@ -965,7 +969,7 @@ export default class Component {
 
 		walk(this.ast.instance.content, {
 			enter(node: Node) {
-				if (/Function/.test(node.type)) {
+				if (regex_contains_term_function.test(node.type)) {
 					return this.skip();
 				}
 
@@ -1089,7 +1093,7 @@ export default class Component {
 
 						this.replace(b`
 							${node.declarations.length ? node : null}
-							${ props.length > 0 && b`let { ${ props } } = $$props;`}
+							${ props.length > 0 && b`let { ${props} } = $$props;`}
 							${inserts}
 						` as any);
 						return this.skip();
@@ -1460,6 +1464,8 @@ export default class Component {
 	}
 }
 
+const regex_valid_tag_name = /^[a-zA-Z][a-zA-Z0-9]*-[a-zA-Z0-9-]+$/;
+
 function process_component_options(component: Component, nodes) {
 	const component_options: ComponentOptions = {
 		immutable: component.compile_options.immutable || false,
@@ -1473,7 +1479,7 @@ function process_component_options(component: Component, nodes) {
 
 	const node = nodes.find(node => node.name === 'svelte:options');
 
-	function get_value(attribute, {code, message}) {
+	function get_value(attribute, { code, message }) {
 		const { value } = attribute;
 		const chunk = value[0];
 
@@ -1505,7 +1511,7 @@ function process_component_options(component: Component, nodes) {
 							return component.error(attribute, compiler_errors.invalid_tag_attribute);
 						}
 
-						if (tag && !/^[a-zA-Z][a-zA-Z0-9]*-[a-zA-Z0-9-]+$/.test(tag)) {
+						if (tag && !regex_valid_tag_name.test(tag)) {
 							return component.error(attribute, compiler_errors.invalid_tag_property);
 						}
 

src/compiler/compile/css/Selector.ts

@@ -9,6 +9,7 @@ import EachBlock from '../nodes/EachBlock';
 import IfBlock from '../nodes/IfBlock';
 import AwaitBlock from '../nodes/AwaitBlock';
 import compiler_errors from '../compiler_errors';
+import { regex_starts_with_whitespace, regex_ends_with_whitespace } from '../../utils/patterns';
 
 enum BlockAppliesToNode {
 	NotPossible,
@@ -25,6 +26,8 @@ const whitelist_attribute_selector = new Map([
 	['dialog', new Set(['open'])]
 ]);
 
+const regex_is_single_css_selector = /[^\\],(?!([^([]+[^\\]|[^([\\])[)\]])/;
+
 export default class Selector {
 	node: CssNode;
 	stylesheet: Stylesheet;
@@ -157,7 +160,7 @@ export default class Selector {
 		for (const block of this.blocks) {
 			for (const selector of block.selectors) {
 				if (selector.type === 'PseudoClassSelector' && selector.name === 'global') {
-					if (/[^\\],(?!([^([]+[^\\]|[^([\\])[)\]])/.test(selector.children[0].value)) {
+					if (regex_is_single_css_selector.test(selector.children[0].value)) {
 						component.error(selector, compiler_errors.css_invalid_global_selector);
 					}
 				}
@@ -281,12 +284,14 @@ function apply_selector(blocks: Block[], node: Element, to_encapsulate: Array<{
 	return true;
 }
 
+const regex_backslash_and_following_character = /\\(.)/g;
+
 function block_might_apply_to_node(block: Block, node: Element): BlockAppliesToNode {
 	let i = block.selectors.length;
 
 	while (i--) {
 		const selector = block.selectors[i];
-		const name = typeof selector.name === 'string' && selector.name.replace(/\\(.)/g, '$1');
+		const name = typeof selector.name === 'string' && selector.name.replace(regex_backslash_and_following_character, '$1');
 
 		if (selector.type === 'PseudoClassSelector' && (name === 'host' || name === 'root')) {
 			return BlockAppliesToNode.NotPossible;
@@ -371,7 +376,7 @@ function attribute_matches(node: CssNode, name: string, expected_value: string,
 			const start_with_space = [];
 			const remaining = [];
 			current_possible_values.forEach((current_possible_value: string) => {
-				if (/^\s/.test(current_possible_value)) {
+				if (regex_starts_with_whitespace.test(current_possible_value)) {
 					start_with_space.push(current_possible_value);
 				} else {
 					remaining.push(current_possible_value);
@@ -392,7 +397,7 @@ function attribute_matches(node: CssNode, name: string, expected_value: string,
 				prev_values = combined;
 
 				start_with_space.forEach((value: string) => {
-					if (/\s$/.test(value)) {
+					if (regex_ends_with_whitespace.test(value)) {
 						possible_values.add(value);
 					} else {
 						prev_values.push(value);
@@ -406,7 +411,7 @@ function attribute_matches(node: CssNode, name: string, expected_value: string,
 		}
 
 		current_possible_values.forEach((current_possible_value: string) => {
-			if (/\s$/.test(current_possible_value)) {
+			if (regex_ends_with_whitespace.test(current_possible_value)) {
 				possible_values.add(current_possible_value);
 			} else {
 				prev_values.push(current_possible_value);

src/compiler/compile/css/Stylesheet.ts

@@ -9,9 +9,12 @@ import hash from '../utils/hash';
 import compiler_warnings from '../compiler_warnings';
 import { extract_ignores_above_position } from '../../utils/extract_svelte_ignore';
 import { push_array } from '../../utils/push_array';
+import { regex_only_whitespaces, regex_whitespace } from '../../utils/patterns';
+
+const regex_css_browser_prefix = /^-((webkit)|(moz)|(o)|(ms))-/;
 
 function remove_css_prefix(name: string): string {
-	return name.replace(/^-((webkit)|(moz)|(o)|(ms))-/, '');
+	return name.replace(regex_css_browser_prefix, '');
 }
 
 const is_keyframes_node = (node: CssNode) =>
@@ -147,10 +150,10 @@ class Declaration {
 
 		// Don't minify whitespace in custom properties, since some browsers (Chromium < 99)
 		// treat --foo: ; and --foo:; differently
-		if (first.type === 'Raw' && /^\s+$/.test(first.value)) return;
+		if (first.type === 'Raw' && regex_only_whitespaces.test(first.value)) return;
 
 		let start = first.start;
-		while (/\s/.test(code.original[start])) start += 1;
+		while (regex_whitespace.test(code.original[start])) start += 1;
 
 		if (start - c > 1) {
 			code.overwrite(c, start, ':');

src/compiler/compile/index.ts

@@ -35,6 +35,9 @@ const valid_options = [
 	'cssHash'
 ];
 
+const regex_valid_identifier = /^[a-zA-Z_$][a-zA-Z_$0-9]*$/;
+const regex_starts_with_lowercase_character = /^[a-z]/;
+
 function validate_options(options: CompileOptions, warnings: Warning[]) {
 	const { name, filename, loopGuardTimeout, dev, namespace } = options;
 
@@ -48,11 +51,11 @@ function validate_options(options: CompileOptions, warnings: Warning[]) {
 		}
 	});
 
-	if (name && !/^[a-zA-Z_$][a-zA-Z_$0-9]*$/.test(name)) {
+	if (name && !regex_valid_identifier.test(name)) {
 		throw new Error(`options.name must be a valid identifier (got '${name}')`);
 	}
 
-	if (name && /^[a-z]/.test(name)) {
+	if (name && regex_starts_with_lowercase_character.test(name)) {
 		const message = 'options.name should be capitalised';
 		warnings.push({
 			code: 'options-lowercase-name',

src/compiler/compile/nodes/Binding.ts

@@ -3,7 +3,7 @@ import get_object from '../utils/get_object';
 import Expression from './shared/Expression';
 import Component from '../Component';
 import TemplateScope from './shared/TemplateScope';
-import {dimensions} from '../../utils/patterns';
+import { regex_dimensions } from '../../utils/patterns';
 import { Node as ESTreeNode } from 'estree';
 import { TemplateNode } from '../../interfaces';
 import Element from './Element';
@@ -88,7 +88,7 @@ export default class Binding extends Node {
 		const type = parent.get_static_attribute_value('type');
 
 		this.is_readonly =
-			dimensions.test(this.name) ||
+			regex_dimensions.test(this.name) ||
 			(isElement(parent) &&
 				((parent.is_media_node() && read_only_media_attributes.has(this.name)) ||
 					(parent.name === 'input' && type === 'file')) /* TODO others? */);

src/compiler/compile/nodes/Element.ts

@@ -11,7 +11,7 @@ import StyleDirective from './StyleDirective';
 import Text from './Text';
 import { namespaces } from '../../utils/namespaces';
 import map_children from './shared/map_children';
-import { dimensions, start_newline } from '../../utils/patterns';
+import { regex_dimensions, regex_starts_with_newline, regex_non_whitespace_character } from '../../utils/patterns';
 import fuzzymatch from '../../utils/fuzzymatch';
 import list from '../../utils/list';
 import Let from './Let';
@@ -203,6 +203,10 @@ function is_valid_aria_attribute_value(schema: ARIAPropertyDefinition, value: st
 	}
 }
 
+const regex_any_repeated_whitespaces = /[\s]+/g;
+const regex_heading_tags = /^h[1-6]$/;
+const regex_illegal_attribute_character = /(^[0-9-.])|[\^$@%&#?!|()[\]{}^*+~;]/;
+
 export default class Element extends Node {
 	type: 'Element';
 	name: string;
@@ -253,7 +257,7 @@ export default class Element extends Node {
 					// places if there's another newline afterwards.
 					// see https://html.spec.whatwg.org/multipage/syntax.html#element-restrictions
 					// see https://html.spec.whatwg.org/multipage/grouping-content.html#the-pre-element
-					first.data = first.data.replace(start_newline, '');
+					first.data = first.data.replace(regex_starts_with_newline, '');
 				}
 			}
 
@@ -398,7 +402,7 @@ export default class Element extends Node {
 
 			// Errors
 
-			if (/(^[0-9-.])|[\^$@%&#?!|()[\]{}^*+~;]/.test(name)) {
+			if (regex_illegal_attribute_character.test(name)) {
 				return component.error(attribute, compiler_errors.illegal_attribute(name));
 			}
 
@@ -464,7 +468,7 @@ export default class Element extends Node {
 					component.warn(attribute, compiler_warnings.a11y_unknown_aria_attribute(type, match));
 				}
 
-				if (name === 'aria-hidden' && /^h[1-6]$/.test(this.name)) {
+				if (name === 'aria-hidden' && regex_heading_tags.test(this.name)) {
 					component.warn(attribute, compiler_warnings.a11y_hidden(this.name));
 				}
 
@@ -729,7 +733,7 @@ export default class Element extends Node {
 		if (this.name === 'figure') {
 			const children = this.children.filter(node => {
 				if (node.type === 'Comment') return false;
-				if (node.type === 'Text') return /\S/.test(node.data);
+				if (node.type === 'Text') return regex_non_whitespace_character.test(node.data);
 				return true;
 			});
 
@@ -861,7 +865,7 @@ export default class Element extends Node {
 				if (this.name !== 'video') {
 					return component.error(binding, compiler_errors.invalid_binding_element_with('<video>', name));
 				}
-			} else if (dimensions.test(name)) {
+			} else if (regex_dimensions.test(name)) {
 				if (this.name === 'svg' && (name === 'offsetWidth' || name === 'offsetHeight')) {
 					return component.error(binding, compiler_errors.invalid_binding_on(binding.name, `<svg>. Use '${name.replace('offset', 'client')}' instead`));
 				} else if (is_svg(this.name)) {
@@ -988,7 +992,7 @@ export default class Element extends Node {
 			if (attribute && !attribute.is_true) {
 				attribute.chunks.forEach((chunk, index) => {
 					if (chunk.type === 'Text') {
-						let data = chunk.data.replace(/[\s\n\t]+/g, ' ');
+						let data = chunk.data.replace(regex_any_repeated_whitespaces, ' ');
 						if (index === 0) {
 							data = data.trimLeft();
 						} else if (index === attribute.chunks.length - 1) {
@@ -1002,23 +1006,27 @@ export default class Element extends Node {
 	}
 }
 
+const regex_starts_with_vovel = /^[aeiou]/;
+
 function should_have_attribute(
 	node,
 	attributes: string[],
 	name = node.name
 ) {
-	const article = /^[aeiou]/.test(attributes[0]) ? 'an' : 'a';
+	const article = regex_starts_with_vovel.test(attributes[0]) ? 'an' : 'a';
 	const sequence = attributes.length > 1 ?
 		attributes.slice(0, -1).join(', ') + ` or ${attributes[attributes.length - 1]}` :
 		attributes[0];
 
 	node.component.warn(node, compiler_warnings.a11y_missing_attribute(name, article, sequence));
 }
 
+const regex_minus_sign = /-/;
+
 function within_custom_element(parent: INode) {
 	while (parent) {
 		if (parent.type === 'InlineComponent') return false;
-		if (parent.type === 'Element' && /-/.test(parent.name)) return true;
+		if (parent.type === 'Element' && regex_minus_sign.test(parent.name)) return true;
 		parent = parent.parent;
 	}
 	return false;

src/compiler/compile/nodes/EventHandler.ts

@@ -6,6 +6,8 @@ import { Identifier } from 'estree';
 import TemplateScope from './shared/TemplateScope';
 import { TemplateNode } from '../../interfaces';
 
+const regex_contains_term_function_expression = /FunctionExpression/;
+
 export default class EventHandler extends Node {
 	type: 'EventHandler';
 	name: string;
@@ -25,7 +27,7 @@ export default class EventHandler extends Node {
 			this.expression = new Expression(component, this, template_scope, info.expression);
 			this.uses_context = this.expression.uses_context;
 
-			if (/FunctionExpression/.test(info.expression.type) && info.expression.params.length === 0) {
+			if (regex_contains_term_function_expression.test(info.expression.type) && info.expression.params.length === 0) {
 				// TODO make this detection more accurate — if `event.preventDefault` isn't called, and
 				// `event` is passed to another function, we can make it passive
 				this.can_make_passive = true;
@@ -55,7 +57,7 @@ export default class EventHandler extends Node {
 		}
 		const node = this.expression.node;
 
-		if (/FunctionExpression/.test(node.type)) {
+		if (regex_contains_term_function_expression.test(node.type)) {
 			return false;
 		}
 

src/compiler/compile/nodes/Head.ts

@@ -5,6 +5,7 @@ import Component from '../Component';
 import TemplateScope from './shared/TemplateScope';
 import { TemplateNode } from '../../interfaces';
 import compiler_errors from '../compiler_errors';
+import { regex_non_whitespace_character } from '../../utils/patterns';
 
 export default class Head extends Node {
 	type: 'Head';
@@ -20,7 +21,7 @@ export default class Head extends Node {
 		}
 
 		this.children = map_children(component, parent, scope, info.children.filter(child => {
-			return (child.type !== 'Text' || /\S/.test(child.data));
+			return (child.type !== 'Text' || regex_non_whitespace_character.test(child.data));
 		}));
 
 		if (this.children.length > 0) {