optimize `.replace() calls

src/compiler/compile/render_dom/Block.ts

@@ -23,6 +23,8 @@ export interface BlockOptions {
 	dependencies?: Set<string>;
 }
 
+const regex_double_quotes = /"/g;
+
 export default class Block {
 	parent?: Block;
 	renderer: Renderer;
@@ -415,7 +417,7 @@ export default class Block {
 						block: ${block},
 						id: ${this.name || 'create_fragment'}.name,
 						type: "${this.type}",
-						source: "${this.comment ? this.comment.replace(/"/g, '\\"') : ''}",
+						source: "${this.comment ? this.comment.replace(regex_double_quotes, '\\"') : ''}",
 						ctx: #ctx
 					});
 					return ${block};`

src/compiler/compile/render_dom/index.ts

@@ -13,6 +13,8 @@ import { flatten } from '../../utils/flatten';
 import check_enable_sourcemap from '../utils/check_enable_sourcemap';
 import { push_array } from '../../utils/push_array';
 
+const regex_backslash = /\\/g;
+
 export default function dom(
 	component: Component,
 	options: CompileOptions
@@ -530,7 +532,7 @@ export default function dom(
 				constructor(options) {
 					super();
 
-					${css.code && b`this.shadowRoot.innerHTML = \`<style>${css.code.replace(/\\/g, '\\\\')}${css_sourcemap_enabled && options.dev ? `\n/*# sourceMappingURL=${css.map.toUrl()} */` : ''}</style>\`;`}
+					${css.code && b`this.shadowRoot.innerHTML = \`<style>${css.code.replace(regex_backslash, '\\\\')}${css_sourcemap_enabled && options.dev ? `\n/*# sourceMappingURL=${css.map.toUrl()} */` : ''}</style>\`;`}
 
 					@init(this, { target: this.shadowRoot, props: ${init_props}, customElement: true }, ${definition}, ${has_create_fragment ? 'create_fragment' : 'null'}, ${not_equal}, ${prop_indexes}, null, ${dirty});
 

src/compiler/compile/render_dom/wrappers/Element/Attribute.ts

@@ -46,6 +46,8 @@ export class BaseAttributeWrapper {
 }
 
 const regex_minus_sign = /-/;
+const regex_invalid_variable_identifier_characters = /[^a-zA-Z_$]/g; // is 0-9 missing?
+const regex_double_quotes = /"/g;
 
 export default class AttributeWrapper extends BaseAttributeWrapper {
 	node: Attribute;
@@ -198,7 +200,7 @@ export default class AttributeWrapper extends BaseAttributeWrapper {
 
 	get_init(block: Block, value) {
 		this.last = this.should_cache && block.get_unique_name(
-			`${this.parent.var.name}_${this.name.replace(/[^a-zA-Z_$]/g, '_')}_value`
+			`${this.parent.var.name}_${this.name.replace(regex_invalid_variable_identifier_characters, '_')}_value`
 		);
 
 		if (this.should_cache) block.add_variable(this.last);
@@ -315,7 +317,7 @@ export default class AttributeWrapper extends BaseAttributeWrapper {
 
 		return `="${value.map(chunk => {
 			return chunk.type === 'Text'
-				? chunk.data.replace(/"/g, '\\"')
+				? chunk.data.replace(regex_double_quotes, '\\"')
 				: `\${${chunk.manipulate()}}`;
 		}).join('')}"`;
 	}

src/compiler/compile/render_dom/wrappers/Element/StyleAttribute.ts

@@ -108,6 +108,8 @@ function optimize_style(value: Array<Text | Expression>) {
 	return props;
 }
 
+const regex_important_flag = /\s*!important\s*$/;
+
 function get_style_value(chunks: Array<Text | Expression>) {
 	const value: Array<Text | Expression> = [];
 
@@ -174,9 +176,9 @@ function get_style_value(chunks: Array<Text | Expression>) {
 	let important = false;
 
 	const last_chunk = value[value.length - 1];
-	if (last_chunk && last_chunk.type === 'Text' && /\s*!important\s*$/.test(last_chunk.data)) {
+	if (last_chunk && last_chunk.type === 'Text' && regex_important_flag.test(last_chunk.data)) {
 		important = true;
-		last_chunk.data = last_chunk.data.replace(/\s*!important\s*$/, '');
+		last_chunk.data = last_chunk.data.replace(regex_important_flag, '');
 		if (!last_chunk.data) value.pop();
 	}
 

src/compiler/compile/render_dom/wrappers/Element/index.ts

@@ -136,6 +136,8 @@ const events = [
 ];
 
 const CHILD_DYNAMIC_ELEMENT_BLOCK = 'child_dynamic_element';
+const regex_invalid_variable_identifier_characters = /[^a-zA-Z0-9_$]/g;
+const regex_minus_signs = /-/g;
 
 export default class ElementWrapper extends Wrapper {
 	node: Element;
@@ -182,7 +184,7 @@ export default class ElementWrapper extends Wrapper {
 
 		this.var = {
 			type: 'Identifier',
-			name: node.name.replace(/[^a-zA-Z0-9_$]/g, '_')
+			name: node.name.replace(regex_invalid_variable_identifier_characters, '_')
 		};
 
 		this.void = is_void(node.name);
@@ -320,19 +322,19 @@ export default class ElementWrapper extends Wrapper {
 				}
 			} else if (${previous_tag}) {
 				${
-					has_transitions
-						? b`
+			has_transitions
+				? b`
 							@group_outros();
 							@transition_out(${this.var}, 1, 1, () => {
 								${this.var} = null;
 							});
 							@check_outros();
 						`
-						: b`
+			: b`
 							${this.var}.d(1);
 							${this.var} = null;
 						`
-				}
+			}
 			}
 			${previous_tag} = ${tag};
 		`);
@@ -547,7 +549,7 @@ export default class ElementWrapper extends Wrapper {
 		}
 	}
 
-	add_directives_in_order (block: Block) {
+	add_directives_in_order(block: Block) {
 		type OrderedAttribute = EventHandler | BindingGroup | Binding | Action;
 
 		const binding_groups = events
@@ -561,7 +563,7 @@ export default class ElementWrapper extends Wrapper {
 
 		const this_binding = this.bindings.find(b => b.node.name === 'this');
 
-		function getOrder (item: OrderedAttribute) {
+		function getOrder(item: OrderedAttribute) {
 			if (item instanceof EventHandler) {
 				return item.node.start;
 			} else if (item instanceof Binding) {
@@ -674,9 +676,9 @@ export default class ElementWrapper extends Wrapper {
 			function ${handler}(${params}) {
 				${binding_group.bindings.map(b => b.handler.mutation)}
 				${Array.from(dependencies)
-					.filter(dep => dep[0] !== '$')
-					.filter(dep => !contextual_dependencies.has(dep))
-					.map(dep => b`${this.renderer.invalidate(dep)};`)}
+			.filter(dep => dep[0] !== '$')
+			.filter(dep => !contextual_dependencies.has(dep))
+			.map(dep => b`${this.renderer.invalidate(dep)};`)}
 			}
 		`);
 
@@ -1100,7 +1102,7 @@ export default class ElementWrapper extends Wrapper {
 			const snippet = expression.manipulate(block);
 			let cached_snippet;
 			if (should_cache) {
-				cached_snippet = block.get_unique_name(`style_${name.replace(/-/g, '_')}`);
+				cached_snippet = block.get_unique_name(`style_${name.replace(regex_minus_signs, '_')}`);
 				block.add_variable(cached_snippet, snippet);
 			}
 
@@ -1154,10 +1156,14 @@ function to_html(wrappers: Array<ElementWrapper | TextWrapper | MustacheTagWrapp
 				can_use_raw_text
 			);
 
+			const regex_backslashes = /\\/g;
+			const regex_backticks = /`/g;
+			const regex_dollar_signs = /\$/g;
+
 			state.quasi.value.raw += (raw ? wrapper.data : escape_html(wrapper.data))
-				.replace(/\\/g, '\\\\')
-				.replace(/`/g, '\\`')
-				.replace(/\$/g, '\\$');
+				.replace(regex_backslashes, '\\\\')
+				.replace(regex_backticks, '\\`')
+				.replace(regex_dollar_signs, '\\$');
 		} else if (wrapper instanceof MustacheTagWrapper || wrapper instanceof RawMustacheTagWrapper) {
 			literal.quasis.push(state.quasi);
 			literal.expressions.push(wrapper.node.expression.manipulate(block));

src/compiler/compile/render_dom/wrappers/InlineComponent/index.ts

@@ -24,6 +24,8 @@ import { namespaces } from '../../../../utils/namespaces';
 
 type SlotDefinition = { block: Block; scope: TemplateScope; get_context?: Node; get_changes?: Node };
 
+const regex_invalid_variable_identifier_characters = /[^a-zA-Z_$]/g; // is 0-9 missing?
+
 export default class InlineComponentWrapper extends Wrapper {
 	var: Identifier;
 	slots: Map<string, SlotDefinition> = new Map();
@@ -596,7 +598,7 @@ export default class InlineComponentWrapper extends Wrapper {
 		this.node.css_custom_properties.forEach((attr) => {
 			const dependencies = attr.get_dependencies();
 			const should_cache = attr.should_cache();
-			const last = should_cache &&	block.get_unique_name(`${attr.name.replace(/[^a-zA-Z_$]/g, '_')}_last`);
+			const last = should_cache &&	block.get_unique_name(`${attr.name.replace(regex_invalid_variable_identifier_characters, '_')}_last`);
 			if (should_cache) block.add_variable(last);
 			const value = attr.get_value(block);
 			const init = should_cache ? x`${last} = ${value}` : value;

src/compiler/compile/render_dom/wrappers/shared/add_actions.ts

@@ -12,6 +12,8 @@ export default function add_actions(
 	actions.forEach(action => add_action(block, target, action));
 }
 
+const regex_invalid_variable_identifier_characters = /[^a-zA-Z0-9_$]/g;
+
 export function add_action(block: Block, target: string | Expression, action: Action) {
 	const { expression, template_scope } = action;
 	let snippet;
@@ -23,7 +25,7 @@ export function add_action(block: Block, target: string | Expression, action: Ac
 	}
 
 	const id = block.get_unique_name(
-		`${action.name.replace(/[^a-zA-Z0-9_$]/g, '_')}_action`
+		`${action.name.replace(regex_invalid_variable_identifier_characters, '_')}_action`
 	);
 
 	block.add_variable(id);

src/compiler/compile/render_dom/wrappers/shared/create_debugging_comment.ts

@@ -1,6 +1,8 @@
 import Component from '../../../Component';
 import { INode } from '../../../nodes/interfaces';
 
+const regex_whitespace_characters = /\s/g;
+
 export default function create_debugging_comment(
 	node: INode,
 	component: Component
@@ -36,5 +38,5 @@ export default function create_debugging_comment(
 	const start = locate(c);
 	const loc = `(${start.line}:${start.column})`;
 
-	return `${loc} ${source.slice(c, d)}`.replace(/\s/g, ' ');
+	return `${loc} ${source.slice(c, d)}`.replace(regex_whitespace_characters, ' ');
 }

src/compiler/compile/render_ssr/handlers/shared/get_attribute_value.ts

@@ -15,13 +15,15 @@ export function get_class_attribute_value(attribute: Attribute): ESTreeExpressio
 	return get_attribute_value(attribute);
 }
 
+const regex_double_quotes = /"/g;
+
 export function get_attribute_value(attribute: Attribute): ESTreeExpression {
 	if (attribute.chunks.length === 0) return x`""`;
 
 	return attribute.chunks
 		.map((chunk) => {
 			return chunk.type === 'Text'
-				? string_literal(chunk.data.replace(/"/g, '"')) as ESTreeExpression
+				? string_literal(chunk.data.replace(regex_double_quotes, '"')) as ESTreeExpression
 				: x`@escape(${chunk.node}, true)`;
 		})
 		.reduce((lhs, rhs) => x`${lhs} + ${rhs}`);

src/compiler/compile/utils/get_name_from_filename.ts

@@ -1,3 +1,10 @@
+const regex_percentage_characters = /%/g;
+const regex_file_ending = /\.[^.]+$/;
+const regex_repeated_invalid_variable_identifier_characters = /[^a-zA-Z_$0-9]+/g;
+const regex_starts_with_underscore = /^_/;
+const regex_ends_with_underscore = /_$/;
+const regex_starts_with_digit = /^(\d)/;
+
 export default function get_name_from_filename(filename: string) {
 	if (!filename) return null;
 
@@ -12,12 +19,12 @@ export default function get_name_from_filename(filename: string) {
 	}
 
 	const base = parts.pop()
-		.replace(/%/g, 'u')
-		.replace(/\.[^.]+$/, '')
-		.replace(/[^a-zA-Z_$0-9]+/g, '_')
-		.replace(/^_/, '')
-		.replace(/_$/, '')
-		.replace(/^(\d)/, '_$1');
+		.replace(regex_percentage_characters, 'u')
+		.replace(regex_file_ending, '')
+		.replace(regex_repeated_invalid_variable_identifier_characters, '_')
+		.replace(regex_starts_with_underscore, '')
+		.replace(regex_ends_with_underscore, '')
+		.replace(regex_starts_with_digit, '_$1');
 
 	if (!base) {
 		throw new Error(`Could not derive component name from file ${filename}`);

src/compiler/compile/utils/hash.ts

@@ -1,6 +1,9 @@
 // https://github.com/darkskyapp/string-hash/blob/master/index.js
+
+const const_return_characters = /\r/g;
+
 export default function hash(str: string): string {
-	str = str.replace(/\r/g, '');
+	str = str.replace(const_return_characters, '');
 	let hash = 5381;
 	let i = str.length;
 

src/compiler/compile/utils/stringify.ts

@@ -19,10 +19,14 @@ const escaped = {
 	'>': '>'
 };
 
+const regex_html_characters_to_escape = /["'&<>]/g;
+
 export function escape_html(html) {
-	return String(html).replace(/["'&<>]/g, match => escaped[match]);
+	return String(html).replace(regex_html_characters_to_escape, match => escaped[match]);
 }
 
+const regex_template_characters_to_escape = /(\${|`|\\)/g;
+
 export function escape_template(str) {
-	return str.replace(/(\${|`|\\)/g, '\\$1');
+	return str.replace(regex_template_characters_to_escape, '\\$1');
 }

src/compiler/parse/index.ts

@@ -15,6 +15,8 @@ interface LastAutoClosedTag {
 	depth: number;
 }
 
+const regex_position_indicator = / \(\d+:\d+\)$/;
+
 export class Parser {
 	readonly template: string;
 	readonly filename?: string;
@@ -93,7 +95,7 @@ export class Parser {
 	acorn_error(err: any) {
 		this.error({
 			code: 'parse-error',
-			message: err.message.replace(/ \(\d+:\d+\)$/, '')
+			message: err.message.replace(regex_position_indicator, '')
 		}, err.pos);
 	}
 

src/compiler/parse/read/context.ts

@@ -11,6 +11,8 @@ import { parse_expression_at } from '../acorn';
 import { Pattern } from 'estree';
 import parser_errors from '../errors';
 
+const regex_not_newline_characters = /[^\n]/g;
+
 export default function read_context(
 	parser: Parser
 ): Pattern & { start: number; end: number } {
@@ -65,7 +67,7 @@ export default function read_context(
 		// so we offset it by removing 1 character in the `space_with_newline`
 		// to achieve that, we remove the 1st space encountered,
 		// so it will not affect the `column` of the node
-		let space_with_newline = parser.template.slice(0, start).replace(/[^\n]/g, ' ');
+		let space_with_newline = parser.template.slice(0, start).replace(regex_not_newline_characters, ' ');
 		const first_space = space_with_newline.indexOf(' ');
 		space_with_newline = space_with_newline.slice(0, first_space) + space_with_newline.slice(first_space + 1);
 

src/compiler/parse/read/script.ts

@@ -4,6 +4,9 @@ import { Script } from '../../interfaces';
 import { Node, Program } from 'estree';
 import parser_errors from '../errors';
 
+const regex_not_newline_characters = /[^\n]/g;
+const regex_closing_script_tag = /<\/script\s*>/;
+
 function get_context(parser: Parser, attributes: any[], start: number): string {
 	const context = attributes.find(attribute => attribute.name === 'context');
 	if (!context) return 'default';
@@ -23,13 +26,13 @@ function get_context(parser: Parser, attributes: any[], start: number): string {
 
 export default function read_script(parser: Parser, start: number, attributes: Node[]): Script {
 	const script_start = parser.index;
-	const data = parser.read_until(/<\/script\s*>/, parser_errors.unclosed_script);
+	const data = parser.read_until(regex_closing_script_tag, parser_errors.unclosed_script);
 	if (parser.index >= parser.template.length) {
 		parser.error(parser_errors.unclosed_script);
 	}
 
-	const source = parser.template.slice(0, script_start).replace(/[^\n]/g, ' ') + data;
-	parser.read(/<\/script\s*>/);
+	const source = parser.template.slice(0, script_start).replace(regex_not_newline_characters, ' ') + data;
+	parser.read(regex_closing_script_tag);
 
 	let ast: Program;