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[RFC] Improve flow typing
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Micha Reiser committed Oct 4, 2020
1 parent e498bee commit ee84ca3
Showing 1 changed file with 117 additions and 90 deletions.
207 changes: 117 additions & 90 deletions packages/babel-types/scripts/generators/flow.js
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Expand Up @@ -8,23 +8,28 @@ const NODE_PREFIX = "BabelNode";

let code = `// NOTE: This file is autogenerated. Do not modify.
// See packages/babel-types/scripts/generators/flow.js for script used.
// @flow
declare class ${NODE_PREFIX}Comment {
declare type ${NODE_PREFIX}BaseComment = {|
value: string;
start: number;
end: number;
loc: ${NODE_PREFIX}SourceLocation;
}
|};
declare class ${NODE_PREFIX}CommentBlock extends ${NODE_PREFIX}Comment {
declare type ${NODE_PREFIX}CommentBlock = {|
...${NODE_PREFIX}BaseComment;
type: "CommentBlock";
}
|};
declare class ${NODE_PREFIX}CommentLine extends ${NODE_PREFIX}Comment {
declare type ${NODE_PREFIX}CommentLine ={|
...${NODE_PREFIX}BaseComment,
type: "CommentLine";
}
|};
declare type ${NODE_PREFIX}Comment = ${NODE_PREFIX}CommentBlock | ${NODE_PREFIX}CommentLine;
declare class ${NODE_PREFIX}SourceLocation {
declare type ${NODE_PREFIX}SourceLocation = {|
start: {
line: number;
column: number;
Expand All @@ -34,18 +39,8 @@ declare class ${NODE_PREFIX}SourceLocation {
line: number;
column: number;
};
}
declare class ${NODE_PREFIX} {
leadingComments?: Array<${NODE_PREFIX}Comment>;
innerComments?: Array<${NODE_PREFIX}Comment>;
trailingComments?: Array<${NODE_PREFIX}Comment>;
start: ?number;
end: ?number;
loc: ?${NODE_PREFIX}SourceLocation;
}\n\n`;

//
|};
\n\n`;

const lines = [];

Expand Down Expand Up @@ -90,33 +85,48 @@ for (const type in t.NODE_FIELDS) {
}
});

code += `declare class ${NODE_PREFIX}${type} extends ${NODE_PREFIX} {
// Flow seems to deoptimize the union type if another type is spread into the node declaration.
// Defining the base props over and over again significantely speeds up the type checking.
code += `declare type ${NODE_PREFIX}${type} = {|
leadingComments?: Array<${NODE_PREFIX}Comment>;
innerComments?: Array<${NODE_PREFIX}Comment>;
trailingComments?: Array<${NODE_PREFIX}Comment>;
start: ?number;
end: ?number;
loc: ?${NODE_PREFIX}SourceLocation,
${struct.join("\n ").trim()}
}\n\n`;
|};\n\n`;

// Flow chokes on super() and import() :/
if (type !== "Super" && type !== "Import") {
lines.push(
`declare function ${toFunctionName(type)}(${args.join(
`declare export function ${toFunctionName(type)}(${args.join(
", "
)}): ${NODE_PREFIX}${type};`
);
} else {
const functionName = toFunctionName(type);
lines.push(
`declare function _${functionName}(${args.join(
`declare var _${functionName}: (${args.join(
", "
)}): ${NODE_PREFIX}${type};`,
)}) => ${NODE_PREFIX}${type};`,
`declare export { _${functionName} as ${functionName} }`
);
}
}

for (let i = 0; i < t.TYPES.length; i++) {
let decl = `declare function is${t.TYPES[i]}(node: ?Object, opts?: ?Object): boolean`;

if (t.NODE_FIELDS[t.TYPES[i]]) {
decl += ` %checks (node instanceof ${NODE_PREFIX}${t.TYPES[i]})`;
const type = t.TYPES[i];
let decl = `declare export function is${type}(node: ?Object, opts?: ?Object): boolean`;

if (t.NODE_FIELDS[type]) {
decl += ` %checks (node != null && node.type === '${type}');`;
} else if (t.FLIPPED_ALIAS_KEYS[type]) {
const types = t.FLIPPED_ALIAS_KEYS[type];
const checks = types.map(t => `node.type === '${t}'`).join(" || ");
decl += ` %checks (node != null && (${checks}));`;
} else {
decl += ";";
}

lines.push(decl);
Expand All @@ -125,124 +135,141 @@ for (let i = 0; i < t.TYPES.length; i++) {
lines.push(
// builders/
// eslint-disable-next-line max-len
`declare function createTypeAnnotationBasedOnTypeof(type: 'string' | 'number' | 'undefined' | 'boolean' | 'function' | 'object' | 'symbol'): ${NODE_PREFIX}TypeAnnotation`,
`declare export function createTypeAnnotationBasedOnTypeof(type: 'string' | 'number' | 'undefined' | 'boolean' | 'function' | 'object' | 'symbol'): ${NODE_PREFIX}TypeAnnotation`,
// eslint-disable-next-line max-len
`declare function createUnionTypeAnnotation(types: Array<${NODE_PREFIX}FlowType>): ${NODE_PREFIX}UnionTypeAnnotation`,
`declare export function createUnionTypeAnnotation(types: Array<${NODE_PREFIX}FlowType>): ${NODE_PREFIX}UnionTypeAnnotation`,
// eslint-disable-next-line max-len
`declare function createFlowUnionType(types: Array<${NODE_PREFIX}FlowType>): ${NODE_PREFIX}UnionTypeAnnotation`,
`declare export function createFlowUnionType(types: Array<${NODE_PREFIX}FlowType>): ${NODE_PREFIX}UnionTypeAnnotation`,
// this smells like "internal API"
// eslint-disable-next-line max-len
`declare function buildChildren(node: { children: Array<${NODE_PREFIX}JSXText | ${NODE_PREFIX}JSXExpressionContainer | ${NODE_PREFIX}JSXSpreadChild | ${NODE_PREFIX}JSXElement | ${NODE_PREFIX}JSXFragment | ${NODE_PREFIX}JSXEmptyExpression> }): Array<${NODE_PREFIX}JSXText | ${NODE_PREFIX}JSXExpressionContainer | ${NODE_PREFIX}JSXSpreadChild | ${NODE_PREFIX}JSXElement | ${NODE_PREFIX}JSXFragment>`,
`declare export function buildChildren(node: { children: Array<${NODE_PREFIX}JSXText | ${NODE_PREFIX}JSXExpressionContainer | ${NODE_PREFIX}JSXSpreadChild | ${NODE_PREFIX}JSXElement | ${NODE_PREFIX}JSXFragment | ${NODE_PREFIX}JSXEmptyExpression> }): Array<${NODE_PREFIX}JSXText | ${NODE_PREFIX}JSXExpressionContainer | ${NODE_PREFIX}JSXSpreadChild | ${NODE_PREFIX}JSXElement | ${NODE_PREFIX}JSXFragment>`,

// clone/
`declare function clone<T>(n: T): T;`,
`declare function cloneDeep<T>(n: T): T;`,
`declare function cloneDeepWithoutLoc<T>(n: T): T;`,
`declare function cloneNode<T>(n: T, deep?: boolean, withoutLoc?: boolean): T;`,
`declare function cloneWithoutLoc<T>(n: T): T;`,
`declare export function clone<T>(n: T): T;`,
`declare export function cloneDeep<T>(n: T): T;`,
`declare export function cloneDeepWithoutLoc<T>(n: T): T;`,
`declare export function cloneNode<T>(n: T, deep?: boolean, withoutLoc?: boolean): T;`,
`declare export function cloneWithoutLoc<T>(n: T): T;`,

// comments/
`declare type CommentTypeShorthand = 'leading' | 'inner' | 'trailing'`,
// eslint-disable-next-line max-len
`declare function addComment<T: Node>(node: T, type: CommentTypeShorthand, content: string, line?: boolean): T`,
`declare export function addComment<T: Node>(node: T, type: CommentTypeShorthand, content: string, line?: boolean): T`,
// eslint-disable-next-line max-len
`declare function addComments<T: Node>(node: T, type: CommentTypeShorthand, comments: Array<Comment>): T`,
`declare function inheritInnerComments(node: Node, parent: Node): void`,
`declare function inheritLeadingComments(node: Node, parent: Node): void`,
`declare function inheritsComments<T: Node>(node: T, parent: Node): void`,
`declare function inheritTrailingComments(node: Node, parent: Node): void`,
`declare function removeComments<T: Node>(node: T): T`,
`declare export function addComments<T: Node>(node: T, type: CommentTypeShorthand, comments: Array<Comment>): T`,
`declare export function inheritInnerComments(node: Node, parent: Node): void`,
`declare export function inheritLeadingComments(node: Node, parent: Node): void`,
`declare export function inheritsComments<T: Node>(node: T, parent: Node): void`,
`declare export function inheritTrailingComments(node: Node, parent: Node): void`,
`declare export function removeComments<T: Node>(node: T): T`,

// converters/
`declare function ensureBlock(node: ${NODE_PREFIX}, key: string): ${NODE_PREFIX}BlockStatement`,
`declare function toBindingIdentifierName(name?: ?string): string`,
`declare export function ensureBlock(node: ${NODE_PREFIX}, key: string): ${NODE_PREFIX}BlockStatement`,
`declare export function toBindingIdentifierName(name?: ?string): string`,
// eslint-disable-next-line max-len
`declare function toBlock(node: ${NODE_PREFIX}Statement | ${NODE_PREFIX}Expression, parent?: ${NODE_PREFIX}Function | null): ${NODE_PREFIX}BlockStatement`,
`declare export function toBlock(node: ${NODE_PREFIX}Statement | ${NODE_PREFIX}Expression, parent?: ${NODE_PREFIX}Function | null): ${NODE_PREFIX}BlockStatement`,
// eslint-disable-next-line max-len
`declare function toComputedKey(node: ${NODE_PREFIX}Method | ${NODE_PREFIX}Property, key?: ${NODE_PREFIX}Expression | ${NODE_PREFIX}Identifier): ${NODE_PREFIX}Expression`,
`declare export function toComputedKey(node: ${NODE_PREFIX}Method | ${NODE_PREFIX}Property, key?: ${NODE_PREFIX}Expression | ${NODE_PREFIX}Identifier): ${NODE_PREFIX}Expression`,
// eslint-disable-next-line max-len
`declare function toExpression(node: ${NODE_PREFIX}ExpressionStatement | ${NODE_PREFIX}Expression | ${NODE_PREFIX}Class | ${NODE_PREFIX}Function): ${NODE_PREFIX}Expression`,
`declare function toIdentifier(name?: ?string): string`,
`declare export function toExpression(node: ${NODE_PREFIX}ExpressionStatement | ${NODE_PREFIX}Expression | ${NODE_PREFIX}Class | ${NODE_PREFIX}Function): ${NODE_PREFIX}Expression`,
`declare export function toIdentifier(name?: ?string): string`,
// eslint-disable-next-line max-len
`declare function toKeyAlias(node: ${NODE_PREFIX}Method | ${NODE_PREFIX}Property, key?: ${NODE_PREFIX}): string`,
`declare export function toKeyAlias(node: ${NODE_PREFIX}Method | ${NODE_PREFIX}Property, key?: ${NODE_PREFIX}): string`,
// toSequenceExpression relies on types that aren't declared in flow
// eslint-disable-next-line max-len
`declare function toStatement(node: ${NODE_PREFIX}Statement | ${NODE_PREFIX}Class | ${NODE_PREFIX}Function | ${NODE_PREFIX}AssignmentExpression, ignore?: boolean): ${NODE_PREFIX}Statement | void`,
`declare function valueToNode(value: any): ${NODE_PREFIX}Expression`,
`declare export function toStatement(node: ${NODE_PREFIX}Statement | ${NODE_PREFIX}Class | ${NODE_PREFIX}Function | ${NODE_PREFIX}AssignmentExpression, ignore?: boolean): ${NODE_PREFIX}Statement | void`,
`declare export function valueToNode(value: any): ${NODE_PREFIX}Expression`,

// modifications/
// eslint-disable-next-line max-len
`declare function removeTypeDuplicates(types: Array<${NODE_PREFIX}FlowType>): Array<${NODE_PREFIX}FlowType>`,
`declare export function removeTypeDuplicates(types: Array<${NODE_PREFIX}FlowType>): Array<${NODE_PREFIX}FlowType>`,
// eslint-disable-next-line max-len
`declare function appendToMemberExpression(member: ${NODE_PREFIX}MemberExpression, append: ${NODE_PREFIX}, computed?: boolean): ${NODE_PREFIX}MemberExpression`,
`declare export function appendToMemberExpression(member: ${NODE_PREFIX}MemberExpression, append: ${NODE_PREFIX}, computed?: boolean): ${NODE_PREFIX}MemberExpression`,
// eslint-disable-next-line max-len
`declare function inherits<T: Node>(child: T, parent: ${NODE_PREFIX} | null | void): T`,
`declare export function inherits<T: Node>(child: T, parent: ${NODE_PREFIX} | null | void): T`,
// eslint-disable-next-line max-len
`declare function prependToMemberExpression(member: ${NODE_PREFIX}MemberExpression, prepend: ${NODE_PREFIX}Expression): ${NODE_PREFIX}MemberExpression`,
`declare function removeProperties<T>(n: T, opts: ?{}): void;`,
`declare function removePropertiesDeep<T>(n: T, opts: ?{}): T;`,
`declare export function prependToMemberExpression(member: ${NODE_PREFIX}MemberExpression, prepend: ${NODE_PREFIX}Expression): ${NODE_PREFIX}MemberExpression`,
`declare export function removeProperties<T>(n: T, opts: ?{}): void;`,
`declare export function removePropertiesDeep<T>(n: T, opts: ?{}): T;`,

// retrievers/
// eslint-disable-next-line max-len
`declare function getBindingIdentifiers(node: ${NODE_PREFIX}, duplicates: boolean, outerOnly?: boolean): { [key: string]: ${NODE_PREFIX}Identifier | Array<${NODE_PREFIX}Identifier> }`,
`declare export function getBindingIdentifiers(node: ${NODE_PREFIX}, duplicates: boolean, outerOnly?: boolean): { [key: string]: ${NODE_PREFIX}Identifier | Array<${NODE_PREFIX}Identifier> }`,
// eslint-disable-next-line max-len
`declare function getOuterBindingIdentifiers(node: Node, duplicates: boolean): { [key: string]: ${NODE_PREFIX}Identifier | Array<${NODE_PREFIX}Identifier> }`,
`declare export function getOuterBindingIdentifiers(node: Node, duplicates: boolean): { [key: string]: ${NODE_PREFIX}Identifier | Array<${NODE_PREFIX}Identifier> }`,

// traverse/
`declare type TraversalAncestors = Array<{
`declare export type TraversalAncestors = Array<{
node: BabelNode,
key: string,
index?: number,
}>;
declare type TraversalHandler<T> = (BabelNode, TraversalAncestors, T) => void;
declare type TraversalHandlers<T> = {
declare export type TraversalHandler<T> = (BabelNode, TraversalAncestors, T) => void;
declare export type TraversalHandlers<T> = {
enter?: TraversalHandler<T>,
exit?: TraversalHandler<T>,
};`.replace(/(^|\n) {2}/g, "$1"),
// eslint-disable-next-line
`declare function traverse<T>(n: BabelNode, TraversalHandler<T> | TraversalHandlers<T>, state?: T): void;`,
`declare function traverseFast<T>(n: Node, h: TraversalHandler<T>, state?: T): void;`,
`declare export function traverse<T>(n: BabelNode, TraversalHandler<T> | TraversalHandlers<T>, state?: T): void;`,
`declare export function traverseFast<T>(n: Node, h: TraversalHandler<T>, state?: T): void;`,

// utils/
// cleanJSXElementLiteralChild is not exported
// inherit is not exported
`declare function shallowEqual(actual: Object, expected: Object): boolean`,
`declare export function shallowEqual(actual: Object, expected: Object): boolean`,

// validators/
// eslint-disable-next-line max-len
`declare function buildMatchMemberExpression(match: string, allowPartial?: boolean): (?BabelNode) => boolean`,
`declare function is(type: string, n: BabelNode, opts: Object): boolean;`,
`declare function isBinding(node: BabelNode, parent: BabelNode, grandparent?: BabelNode): boolean`,
`declare function isBlockScoped(node: BabelNode): boolean`,
`declare function isImmutable(node: BabelNode): boolean`,
`declare function isLet(node: BabelNode): boolean`,
`declare function isNode(node: ?Object): boolean`,
`declare function isNodesEquivalent(a: any, b: any): boolean`,
`declare function isPlaceholderType(placeholderType: string, targetType: string): boolean`,
`declare function isReferenced(node: BabelNode, parent: BabelNode, grandparent?: BabelNode): boolean`,
`declare function isScope(node: BabelNode, parent: BabelNode): boolean`,
`declare function isSpecifierDefault(specifier: BabelNodeModuleSpecifier): boolean`,
`declare function isType(nodetype: ?string, targetType: string): boolean`,
`declare function isValidES3Identifier(name: string): boolean`,
`declare function isValidES3Identifier(name: string): boolean`,
`declare function isValidIdentifier(name: string): boolean`,
`declare function isVar(node: BabelNode): boolean`,
// eslint-disable-next-line max-len
`declare function matchesPattern(node: ?BabelNode, match: string | Array<string>, allowPartial?: boolean): boolean`,
`declare function validate(n: BabelNode, key: string, value: mixed): void;`
`declare export function buildMatchMemberExpression(match: string, allowPartial?: boolean): (?BabelNode) => boolean`,
`declare export function is(type: string, n: BabelNode, opts: Object): boolean;`,
`declare export function isBinding(node: BabelNode, parent: BabelNode, grandparent?: BabelNode): boolean`,
`declare export function isBlockScoped(node: BabelNode): boolean`,
`declare export function isLet(node: BabelNode): boolean %checks (node.type === 'VariableDeclaration')`,
`declare export function isNode(node: ?Object): boolean`,
`declare export function isNodesEquivalent(a: any, b: any): boolean`,
`declare export function isPlaceholderType(placeholderType: string, targetType: string): boolean`,
`declare export function isReferenced(node: BabelNode, parent: BabelNode, grandparent?: BabelNode): boolean`,
`declare export function isScope(node: BabelNode, parent: BabelNode): boolean %checks (node.type === 'BlockStatement' || node.type === 'CatchClause' || node.type === 'DoWhileStatement' || node.type === 'ForInStatement' || node.type === 'ForStatement' || node.type === 'FunctionDeclaration' || node.type === 'FunctionExpression' || node.type === 'Program' || node.type === 'ObjectMethod' || node.type === 'SwitchStatement' || node.type === 'WhileStatement' || node.type === 'ArrowFunctionExpression' || node.type === 'ClassExpression' || node.type === 'ClassDeclaration' || node.type === 'ForOfStatement' || node.type === 'ClassMethod' || node.type === 'ClassPrivateMethod' || node.type === 'TSModuleBlock')`,
`declare export function isSpecifierDefault(specifier: BabelNodeModuleSpecifier): boolean`,
`declare export function isType(nodetype: ?string, targetType: string): boolean`,
`declare export function isValidES3Identifier(name: string): boolean`,
`declare export function isValidES3Identifier(name: string): boolean`,
`declare export function isValidIdentifier(name: string): boolean`,
`declare export function isVar(node: BabelNode): boolean %checks (node.type === 'VariableDeclaration')`,
// eslint-disable-next-line max-len
`declare export function matchesPattern(node: ?BabelNode, match: string | Array<string>, allowPartial?: boolean): boolean`,
`declare export function validate(n: BabelNode, key: string, value: mixed): void;`
);

code += `declare type ${NODE_PREFIX} = ${Object.keys(t.NODE_FIELDS)
.map(type => `${NODE_PREFIX}${type}`)
.join(" | ")};\n`;

for (const type in t.FLIPPED_ALIAS_KEYS) {
const types = t.FLIPPED_ALIAS_KEYS[type];
code += `type ${NODE_PREFIX}${type} = ${types
code += `declare type ${NODE_PREFIX}${type} = ${types
.map(type => `${NODE_PREFIX}${type}`)
.join(" | ")};\n`;
}

// Module level exports without NODE_PREFIX prefix
const aliasedTypes = [
"CommentBlock",
"CommentLine",
"Comment",
"SourceLocation",
...Object.keys(t.NODE_FIELDS),
...Object.keys(t.FLIPPED_ALIAS_KEYS),
];
lines.push(
`declare export type Node = ${NODE_PREFIX};`,
...aliasedTypes.map(
type => `declare export type ${type} = ${NODE_PREFIX}${type};`
)
);

code += `\ndeclare module "@babel/types" {
${lines.join("\n").replace(/\n/g, "\n ").trim()}
}\n`;

//

process.stdout.write(code);

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