/
Expression.ts
430 lines (355 loc) · 12.5 KB
/
Expression.ts
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import Component from '../../Component';
import { walk } from 'estree-walker';
import is_reference from 'is-reference';
import flatten_reference from '../../utils/flatten_reference';
import { create_scopes, Scope, extract_names } from '../../utils/scope';
import { sanitize } from '../../../utils/names';
import TemplateScope from './TemplateScope';
import get_object from '../../utils/get_object';
import Block from '../../render_dom/Block';
import is_dynamic from '../../render_dom/wrappers/shared/is_dynamic';
import { b } from 'code-red';
import { invalidate } from '../../render_dom/invalidate';
import { Node, FunctionExpression, Identifier } from 'estree';
import { INode } from '../interfaces';
import { is_reserved_keyword } from '../../utils/reserved_keywords';
import replace_object from '../../utils/replace_object';
import is_contextual from './is_contextual';
import EachBlock from '../EachBlock';
import { clone } from '../../../utils/clone';
import compiler_errors from '../../compiler_errors';
type Owner = INode;
export default class Expression {
type: 'Expression' = 'Expression';
component: Component;
owner: Owner;
node: Node;
references: Set<string> = new Set();
dependencies: Set<string> = new Set();
contextual_dependencies: Set<string> = new Set();
template_scope: TemplateScope;
scope: Scope;
scope_map: WeakMap<Node, Scope>;
declarations: Array<(Node | Node[])> = [];
uses_context = false;
manipulated: Node;
constructor(component: Component, owner: Owner, template_scope: TemplateScope, info: Node, lazy?: boolean) {
// TODO revert to direct property access in prod?
Object.defineProperties(this, {
component: {
value: component
}
});
this.node = info;
this.template_scope = template_scope;
this.owner = owner;
const { dependencies, contextual_dependencies, references } = this;
let { map, scope } = create_scopes(info);
this.scope = scope;
this.scope_map = map;
const expression = this;
let function_expression;
// discover dependencies, but don't change the code yet
walk(info, {
enter(node: any, parent: any, key: string) {
// don't manipulate shorthand props twice
if (key === 'key' && parent.shorthand) return;
// don't manipulate `import.meta`, `new.target`
if (node.type === 'MetaProperty') return this.skip();
if (map.has(node)) {
scope = map.get(node);
}
if (!function_expression && /FunctionExpression/.test(node.type)) {
function_expression = node;
}
if (is_reference(node, parent)) {
const { name, nodes } = flatten_reference(node);
references.add(name);
if (scope.has(name)) return;
if (name[0] === '$') {
const store_name = name.slice(1);
if (template_scope.names.has(store_name) || scope.has(store_name)) {
return component.error(node, compiler_errors.contextual_store);
}
}
if (template_scope.is_let(name)) {
if (!lazy) {
contextual_dependencies.add(name);
dependencies.add(name);
}
} else if (template_scope.names.has(name)) {
expression.uses_context = true;
contextual_dependencies.add(name);
const owner = template_scope.get_owner(name);
const is_index = owner.type === 'EachBlock' && owner.key && name === owner.index;
if (!lazy || is_index) {
template_scope.dependencies_for_name.get(name).forEach(name => dependencies.add(name));
}
} else {
if (!lazy) {
dependencies.add(name);
}
component.add_reference(node, name);
component.warn_if_undefined(name, nodes[0], template_scope);
}
this.skip();
}
// track any assignments from template expressions as mutable
let names;
let deep = false;
if (function_expression) {
if (node.type === 'AssignmentExpression') {
deep = node.left.type === 'MemberExpression';
names = extract_names(deep ? get_object(node.left) : node.left);
} else if (node.type === 'UpdateExpression') {
names = extract_names(get_object(node.argument));
}
}
if (names) {
names.forEach(name => {
if (template_scope.names.has(name)) {
if (template_scope.is_const(name)) {
component.error(node, compiler_errors.invalid_const_update(name));
}
template_scope.dependencies_for_name.get(name).forEach(name => {
const variable = component.var_lookup.get(name);
if (variable) variable[deep ? 'mutated' : 'reassigned'] = true;
});
const each_block = template_scope.get_owner(name);
(each_block as EachBlock).has_binding = true;
} else {
component.add_reference(node, name);
const variable = component.var_lookup.get(name);
if (variable) variable[deep ? 'mutated' : 'reassigned'] = true;
}
});
}
},
leave(node: Node) {
if (map.has(node)) {
scope = scope.parent;
}
if (node === function_expression) {
function_expression = null;
}
}
});
}
dynamic_dependencies() {
return Array.from(this.dependencies).filter(name => {
if (this.template_scope.is_let(name)) return true;
if (is_reserved_keyword(name)) return true;
const variable = this.component.var_lookup.get(name);
return is_dynamic(variable);
});
}
// TODO move this into a render-dom wrapper?
manipulate(block?: Block, ctx?: string | void) {
// TODO ideally we wouldn't end up calling this method
// multiple times
if (this.manipulated) return this.manipulated;
const {
component,
declarations,
scope_map: map,
template_scope,
owner
} = this;
let scope = this.scope;
let function_expression;
let dependencies: Set<string>;
let contextual_dependencies: Set<string>;
const node = walk(this.node, {
enter(node: any, parent: any) {
if (node.type === 'Property' && node.shorthand) {
node.value = clone(node.value);
node.shorthand = false;
}
if (map.has(node)) {
scope = map.get(node);
}
if (node.type === 'Identifier' && is_reference(node, parent)) {
const { name } = flatten_reference(node);
if (scope.has(name)) return;
if (function_expression) {
if (template_scope.names.has(name)) {
contextual_dependencies.add(name);
template_scope.dependencies_for_name.get(name).forEach(dependency => {
dependencies.add(dependency);
});
} else {
dependencies.add(name);
component.add_reference(node, name); // TODO is this redundant/misplaced?
}
} else if (is_contextual(component, template_scope, name)) {
const reference = block.renderer.reference(node, ctx);
this.replace(reference);
}
this.skip();
}
if (!function_expression) {
if (node.type === 'AssignmentExpression') {
// TODO should this be a warning/error? `<p>{foo = 1}</p>`
}
if (node.type === 'FunctionExpression' || node.type === 'ArrowFunctionExpression') {
function_expression = node;
dependencies = new Set();
contextual_dependencies = new Set();
}
}
},
leave(node: Node, parent: Node) {
if (map.has(node)) scope = scope.parent;
if (node === function_expression) {
const id = component.get_unique_name(
sanitize(get_function_name(node, owner))
);
const declaration = b`const ${id} = ${node}`;
if (owner.type === 'ConstTag') {
let child_scope = scope;
walk(node, {
enter(node: Node, parent: any) {
if (map.has(node)) child_scope = map.get(node);
if (node.type === 'Identifier' && is_reference(node, parent)) {
if (child_scope.has(node.name)) return;
this.replace(block.renderer.reference(node, ctx));
}
},
leave(node: Node) {
if (map.has(node)) child_scope = child_scope.parent;
}
});
} else if (dependencies.size === 0 && contextual_dependencies.size === 0) {
// we can hoist this out of the component completely
component.fully_hoisted.push(declaration);
this.replace(id as any);
component.add_var(node, {
name: id.name,
internal: true,
hoistable: true,
referenced: true
});
} else if (contextual_dependencies.size === 0) {
// function can be hoisted inside the component init
component.partly_hoisted.push(declaration);
block.renderer.add_to_context(id.name);
this.replace(block.renderer.reference(id));
} else {
// we need a combo block/init recipe
const deps = Array.from(contextual_dependencies);
const function_expression = node as FunctionExpression;
const has_args = function_expression.params.length > 0;
function_expression.params = [
...deps.map(name => ({ type: 'Identifier', name } as Identifier)),
...function_expression.params
];
const context_args = deps.map(name => block.renderer.reference(name));
component.partly_hoisted.push(declaration);
block.renderer.add_to_context(id.name);
const callee = block.renderer.reference(id);
this.replace(id as any);
const func_declaration = has_args
? b`function ${id}(...args) {
return ${callee}(${context_args}, ...args);
}`
: b`function ${id}() {
return ${callee}(${context_args});
}`;
if (owner.type === 'Attribute' && owner.parent.name === 'slot') {
const dep_scopes = new Set<INode>(deps.map(name => template_scope.get_owner(name)));
// find the nearest scopes
let node: INode = owner.parent;
while (node && !dep_scopes.has(node)) {
node = node.parent;
}
const func_expression = func_declaration[0];
if (node.type === 'InlineComponent') {
// <Comp let:data />
this.replace(func_expression);
} else {
// {#each}, {#await}
const func_id = component.get_unique_name(id.name + '_func');
block.renderer.add_to_context(func_id.name, true);
// rename #ctx -> child_ctx;
walk(func_expression, {
enter(node: Node) {
if (node.type === 'Identifier' && node.name === '#ctx') {
node.name = 'child_ctx';
}
}
});
// add to get_xxx_context
// child_ctx[x] = function () { ... }
(template_scope.get_owner(deps[0]) as EachBlock).contexts.push({
key: func_id,
modifier: () => func_expression,
default_modifier: node => node
});
this.replace(block.renderer.reference(func_id));
}
} else {
declarations.push(func_declaration);
}
}
function_expression = null;
dependencies = null;
contextual_dependencies = null;
if (parent && parent.type === 'Property') {
parent.method = false;
}
}
if (node.type === 'AssignmentExpression' || node.type === 'UpdateExpression') {
const assignee = node.type === 'AssignmentExpression' ? node.left : node.argument;
const object_name = get_object(assignee).name;
if (scope.has(object_name)) return;
// normally (`a = 1`, `b.c = 2`), there'll be a single name
// (a or b). In destructuring cases (`[d, e] = [e, d]`) there
// may be more, in which case we need to tack the extra ones
// onto the initial function call
const names = new Set(extract_names(assignee as Node));
const traced: Set<string> = new Set();
names.forEach(name => {
const dependencies = template_scope.dependencies_for_name.get(name);
if (dependencies) {
dependencies.forEach(name => traced.add(name));
} else {
traced.add(name);
}
});
const context = block.bindings.get(object_name);
if (context) {
// for `{#each array as item}`
// replace `item = 1` to `each_array[each_index] = 1`, this allow us to mutate the array
// rather than mutating the local `item` variable
const { snippet, object, property } = context;
const replaced: any = replace_object(assignee, snippet);
if (node.type === 'AssignmentExpression') {
node.left = replaced;
} else {
node.argument = replaced;
}
contextual_dependencies.add(object.name);
contextual_dependencies.add(property.name);
}
this.replace(invalidate(block.renderer, scope, node, traced));
}
}
});
if (declarations.length > 0) {
block.maintain_context = true;
declarations.forEach(declaration => {
block.chunks.init.push(declaration);
});
}
return (this.manipulated = node as Node);
}
}
function get_function_name(_node, parent) {
if (parent.type === 'EventHandler') {
return `${parent.name}_handler`;
}
if (parent.type === 'Action') {
return `${parent.name}_function`;
}
return 'func';
}