devsite/node_modules/sucrase/dist/esm/transformers/JSXTransformer.js
2024-07-07 18:49:38 -07:00

734 lines
25 KiB
JavaScript

import XHTMLEntities from "../parser/plugins/jsx/xhtml";
import {JSXRole} from "../parser/tokenizer";
import {TokenType as tt} from "../parser/tokenizer/types";
import {charCodes} from "../parser/util/charcodes";
import getJSXPragmaInfo, {} from "../util/getJSXPragmaInfo";
import Transformer from "./Transformer";
export default class JSXTransformer extends Transformer {
// State for calculating the line number of each JSX tag in development.
__init() {this.lastLineNumber = 1}
__init2() {this.lastIndex = 0}
// In development, variable name holding the name of the current file.
__init3() {this.filenameVarName = null}
// Mapping of claimed names for imports in the automatic transform, e,g.
// {jsx: "_jsx"}. This determines which imports to generate in the prefix.
__init4() {this.esmAutomaticImportNameResolutions = {}}
// When automatically adding imports in CJS mode, we store the variable name
// holding the imported CJS module so we can require it in the prefix.
__init5() {this.cjsAutomaticModuleNameResolutions = {}}
constructor(
rootTransformer,
tokens,
importProcessor,
nameManager,
options,
) {
super();this.rootTransformer = rootTransformer;this.tokens = tokens;this.importProcessor = importProcessor;this.nameManager = nameManager;this.options = options;JSXTransformer.prototype.__init.call(this);JSXTransformer.prototype.__init2.call(this);JSXTransformer.prototype.__init3.call(this);JSXTransformer.prototype.__init4.call(this);JSXTransformer.prototype.__init5.call(this);;
this.jsxPragmaInfo = getJSXPragmaInfo(options);
this.isAutomaticRuntime = options.jsxRuntime === "automatic";
this.jsxImportSource = options.jsxImportSource || "react";
}
process() {
if (this.tokens.matches1(tt.jsxTagStart)) {
this.processJSXTag();
return true;
}
return false;
}
getPrefixCode() {
let prefix = "";
if (this.filenameVarName) {
prefix += `const ${this.filenameVarName} = ${JSON.stringify(this.options.filePath || "")};`;
}
if (this.isAutomaticRuntime) {
if (this.importProcessor) {
// CJS mode: emit require statements for all modules that were referenced.
for (const [path, resolvedName] of Object.entries(this.cjsAutomaticModuleNameResolutions)) {
prefix += `var ${resolvedName} = require("${path}");`;
}
} else {
// ESM mode: consolidate and emit import statements for referenced names.
const {createElement: createElementResolution, ...otherResolutions} =
this.esmAutomaticImportNameResolutions;
if (createElementResolution) {
prefix += `import {createElement as ${createElementResolution}} from "${this.jsxImportSource}";`;
}
const importSpecifiers = Object.entries(otherResolutions)
.map(([name, resolvedName]) => `${name} as ${resolvedName}`)
.join(", ");
if (importSpecifiers) {
const importPath =
this.jsxImportSource + (this.options.production ? "/jsx-runtime" : "/jsx-dev-runtime");
prefix += `import {${importSpecifiers}} from "${importPath}";`;
}
}
}
return prefix;
}
processJSXTag() {
const {jsxRole, start} = this.tokens.currentToken();
// Calculate line number information at the very start (if in development
// mode) so that the information is guaranteed to be queried in token order.
const elementLocationCode = this.options.production ? null : this.getElementLocationCode(start);
if (this.isAutomaticRuntime && jsxRole !== JSXRole.KeyAfterPropSpread) {
this.transformTagToJSXFunc(elementLocationCode, jsxRole);
} else {
this.transformTagToCreateElement(elementLocationCode);
}
}
getElementLocationCode(firstTokenStart) {
const lineNumber = this.getLineNumberForIndex(firstTokenStart);
return `lineNumber: ${lineNumber}`;
}
/**
* Get the line number for this source position. This is calculated lazily and
* must be called in increasing order by index.
*/
getLineNumberForIndex(index) {
const code = this.tokens.code;
while (this.lastIndex < index && this.lastIndex < code.length) {
if (code[this.lastIndex] === "\n") {
this.lastLineNumber++;
}
this.lastIndex++;
}
return this.lastLineNumber;
}
/**
* Convert the current JSX element to a call to jsx, jsxs, or jsxDEV. This is
* the primary transformation for the automatic transform.
*
* Example:
* <div a={1} key={2}>Hello{x}</div>
* becomes
* jsxs('div', {a: 1, children: ["Hello", x]}, 2)
*/
transformTagToJSXFunc(elementLocationCode, jsxRole) {
const isStatic = jsxRole === JSXRole.StaticChildren;
// First tag is always jsxTagStart.
this.tokens.replaceToken(this.getJSXFuncInvocationCode(isStatic));
let keyCode = null;
if (this.tokens.matches1(tt.jsxTagEnd)) {
// Fragment syntax.
this.tokens.replaceToken(`${this.getFragmentCode()}, {`);
this.processAutomaticChildrenAndEndProps(jsxRole);
} else {
// Normal open tag or self-closing tag.
this.processTagIntro();
this.tokens.appendCode(", {");
keyCode = this.processProps(true);
if (this.tokens.matches2(tt.slash, tt.jsxTagEnd)) {
// Self-closing tag, no children to add, so close the props.
this.tokens.appendCode("}");
} else if (this.tokens.matches1(tt.jsxTagEnd)) {
// Tag with children.
this.tokens.removeToken();
this.processAutomaticChildrenAndEndProps(jsxRole);
} else {
throw new Error("Expected either /> or > at the end of the tag.");
}
// If a key was present, move it to its own arg. Note that moving code
// like this will cause line numbers to get out of sync within the JSX
// element if the key expression has a newline in it. This is unfortunate,
// but hopefully should be rare.
if (keyCode) {
this.tokens.appendCode(`, ${keyCode}`);
}
}
if (!this.options.production) {
// If the key wasn't already added, add it now so we can correctly set
// positional args for jsxDEV.
if (keyCode === null) {
this.tokens.appendCode(", void 0");
}
this.tokens.appendCode(`, ${isStatic}, ${this.getDevSource(elementLocationCode)}, this`);
}
// We're at the close-tag or the end of a self-closing tag, so remove
// everything else and close the function call.
this.tokens.removeInitialToken();
while (!this.tokens.matches1(tt.jsxTagEnd)) {
this.tokens.removeToken();
}
this.tokens.replaceToken(")");
}
/**
* Convert the current JSX element to a createElement call. In the classic
* runtime, this is the only case. In the automatic runtime, this is called
* as a fallback in some situations.
*
* Example:
* <div a={1} key={2}>Hello{x}</div>
* becomes
* React.createElement('div', {a: 1, key: 2}, "Hello", x)
*/
transformTagToCreateElement(elementLocationCode) {
// First tag is always jsxTagStart.
this.tokens.replaceToken(this.getCreateElementInvocationCode());
if (this.tokens.matches1(tt.jsxTagEnd)) {
// Fragment syntax.
this.tokens.replaceToken(`${this.getFragmentCode()}, null`);
this.processChildren(true);
} else {
// Normal open tag or self-closing tag.
this.processTagIntro();
this.processPropsObjectWithDevInfo(elementLocationCode);
if (this.tokens.matches2(tt.slash, tt.jsxTagEnd)) {
// Self-closing tag; no children to process.
} else if (this.tokens.matches1(tt.jsxTagEnd)) {
// Tag with children and a close-tag; process the children as args.
this.tokens.removeToken();
this.processChildren(true);
} else {
throw new Error("Expected either /> or > at the end of the tag.");
}
}
// We're at the close-tag or the end of a self-closing tag, so remove
// everything else and close the function call.
this.tokens.removeInitialToken();
while (!this.tokens.matches1(tt.jsxTagEnd)) {
this.tokens.removeToken();
}
this.tokens.replaceToken(")");
}
/**
* Get the code for the relevant function for this context: jsx, jsxs,
* or jsxDEV. The following open-paren is included as well.
*
* These functions are only used for the automatic runtime, so they are always
* auto-imported, but the auto-import will be either CJS or ESM based on the
* target module format.
*/
getJSXFuncInvocationCode(isStatic) {
if (this.options.production) {
if (isStatic) {
return this.claimAutoImportedFuncInvocation("jsxs", "/jsx-runtime");
} else {
return this.claimAutoImportedFuncInvocation("jsx", "/jsx-runtime");
}
} else {
return this.claimAutoImportedFuncInvocation("jsxDEV", "/jsx-dev-runtime");
}
}
/**
* Return the code to use for the createElement function, e.g.
* `React.createElement`, including the following open-paren.
*
* This is the main function to use for the classic runtime. For the
* automatic runtime, this function is used as a fallback function to
* preserve behavior when there is a prop spread followed by an explicit
* key. In that automatic runtime case, the function should be automatically
* imported.
*/
getCreateElementInvocationCode() {
if (this.isAutomaticRuntime) {
return this.claimAutoImportedFuncInvocation("createElement", "");
} else {
const {jsxPragmaInfo} = this;
const resolvedPragmaBaseName = this.importProcessor
? this.importProcessor.getIdentifierReplacement(jsxPragmaInfo.base) || jsxPragmaInfo.base
: jsxPragmaInfo.base;
return `${resolvedPragmaBaseName}${jsxPragmaInfo.suffix}(`;
}
}
/**
* Return the code to use as the component when compiling a shorthand
* fragment, e.g. `React.Fragment`.
*
* This may be called from either the classic or automatic runtime, and
* the value should be auto-imported for the automatic runtime.
*/
getFragmentCode() {
if (this.isAutomaticRuntime) {
return this.claimAutoImportedName(
"Fragment",
this.options.production ? "/jsx-runtime" : "/jsx-dev-runtime",
);
} else {
const {jsxPragmaInfo} = this;
const resolvedFragmentPragmaBaseName = this.importProcessor
? this.importProcessor.getIdentifierReplacement(jsxPragmaInfo.fragmentBase) ||
jsxPragmaInfo.fragmentBase
: jsxPragmaInfo.fragmentBase;
return resolvedFragmentPragmaBaseName + jsxPragmaInfo.fragmentSuffix;
}
}
/**
* Return code that invokes the given function.
*
* When the imports transform is enabled, use the CJSImportTransformer
* strategy of using `.call(void 0, ...` to avoid passing a `this` value in a
* situation that would otherwise look like a method call.
*/
claimAutoImportedFuncInvocation(funcName, importPathSuffix) {
const funcCode = this.claimAutoImportedName(funcName, importPathSuffix);
if (this.importProcessor) {
return `${funcCode}.call(void 0, `;
} else {
return `${funcCode}(`;
}
}
claimAutoImportedName(funcName, importPathSuffix) {
if (this.importProcessor) {
// CJS mode: claim a name for the module and mark it for import.
const path = this.jsxImportSource + importPathSuffix;
if (!this.cjsAutomaticModuleNameResolutions[path]) {
this.cjsAutomaticModuleNameResolutions[path] =
this.importProcessor.getFreeIdentifierForPath(path);
}
return `${this.cjsAutomaticModuleNameResolutions[path]}.${funcName}`;
} else {
// ESM mode: claim a name for this function and add it to the names that
// should be auto-imported when the prefix is generated.
if (!this.esmAutomaticImportNameResolutions[funcName]) {
this.esmAutomaticImportNameResolutions[funcName] = this.nameManager.claimFreeName(
`_${funcName}`,
);
}
return this.esmAutomaticImportNameResolutions[funcName];
}
}
/**
* Process the first part of a tag, before any props.
*/
processTagIntro() {
// Walk forward until we see one of these patterns:
// jsxName to start the first prop, preceded by another jsxName to end the tag name.
// jsxName to start the first prop, preceded by greaterThan to end the type argument.
// [open brace] to start the first prop.
// [jsxTagEnd] to end the open-tag.
// [slash, jsxTagEnd] to end the self-closing tag.
let introEnd = this.tokens.currentIndex() + 1;
while (
this.tokens.tokens[introEnd].isType ||
(!this.tokens.matches2AtIndex(introEnd - 1, tt.jsxName, tt.jsxName) &&
!this.tokens.matches2AtIndex(introEnd - 1, tt.greaterThan, tt.jsxName) &&
!this.tokens.matches1AtIndex(introEnd, tt.braceL) &&
!this.tokens.matches1AtIndex(introEnd, tt.jsxTagEnd) &&
!this.tokens.matches2AtIndex(introEnd, tt.slash, tt.jsxTagEnd))
) {
introEnd++;
}
if (introEnd === this.tokens.currentIndex() + 1) {
const tagName = this.tokens.identifierName();
if (startsWithLowerCase(tagName)) {
this.tokens.replaceToken(`'${tagName}'`);
}
}
while (this.tokens.currentIndex() < introEnd) {
this.rootTransformer.processToken();
}
}
/**
* Starting at the beginning of the props, add the props argument to
* React.createElement, including the comma before it.
*/
processPropsObjectWithDevInfo(elementLocationCode) {
const devProps = this.options.production
? ""
: `__self: this, __source: ${this.getDevSource(elementLocationCode)}`;
if (!this.tokens.matches1(tt.jsxName) && !this.tokens.matches1(tt.braceL)) {
if (devProps) {
this.tokens.appendCode(`, {${devProps}}`);
} else {
this.tokens.appendCode(`, null`);
}
return;
}
this.tokens.appendCode(`, {`);
this.processProps(false);
if (devProps) {
this.tokens.appendCode(` ${devProps}}`);
} else {
this.tokens.appendCode("}");
}
}
/**
* Transform the core part of the props, assuming that a { has already been
* inserted before us and that a } will be inserted after us.
*
* If extractKeyCode is true (i.e. when using any jsx... function), any prop
* named "key" has its code captured and returned rather than being emitted to
* the output code. This shifts line numbers, and emitting the code later will
* correct line numbers again. If no key is found or if extractKeyCode is
* false, this function returns null.
*/
processProps(extractKeyCode) {
let keyCode = null;
while (true) {
if (this.tokens.matches2(tt.jsxName, tt.eq)) {
// This is a regular key={value} or key="value" prop.
const propName = this.tokens.identifierName();
if (extractKeyCode && propName === "key") {
if (keyCode !== null) {
// The props list has multiple keys. Different implementations are
// inconsistent about what to do here: as of this writing, Babel and
// swc keep the *last* key and completely remove the rest, while
// TypeScript uses the *first* key and leaves the others as regular
// props. The React team collaborated with Babel on the
// implementation of this behavior, so presumably the Babel behavior
// is the one to use.
// Since we won't ever be emitting the previous key code, we need to
// at least emit its newlines here so that the line numbers match up
// in the long run.
this.tokens.appendCode(keyCode.replace(/[^\n]/g, ""));
}
// key
this.tokens.removeToken();
// =
this.tokens.removeToken();
const snapshot = this.tokens.snapshot();
this.processPropValue();
keyCode = this.tokens.dangerouslyGetAndRemoveCodeSinceSnapshot(snapshot);
// Don't add a comma
continue;
} else {
this.processPropName(propName);
this.tokens.replaceToken(": ");
this.processPropValue();
}
} else if (this.tokens.matches1(tt.jsxName)) {
// This is a shorthand prop like <input disabled />.
const propName = this.tokens.identifierName();
this.processPropName(propName);
this.tokens.appendCode(": true");
} else if (this.tokens.matches1(tt.braceL)) {
// This is prop spread, like <div {...getProps()}>, which we can pass
// through fairly directly as an object spread.
this.tokens.replaceToken("");
this.rootTransformer.processBalancedCode();
this.tokens.replaceToken("");
} else {
break;
}
this.tokens.appendCode(",");
}
return keyCode;
}
processPropName(propName) {
if (propName.includes("-")) {
this.tokens.replaceToken(`'${propName}'`);
} else {
this.tokens.copyToken();
}
}
processPropValue() {
if (this.tokens.matches1(tt.braceL)) {
this.tokens.replaceToken("");
this.rootTransformer.processBalancedCode();
this.tokens.replaceToken("");
} else if (this.tokens.matches1(tt.jsxTagStart)) {
this.processJSXTag();
} else {
this.processStringPropValue();
}
}
processStringPropValue() {
const token = this.tokens.currentToken();
const valueCode = this.tokens.code.slice(token.start + 1, token.end - 1);
const replacementCode = formatJSXTextReplacement(valueCode);
const literalCode = formatJSXStringValueLiteral(valueCode);
this.tokens.replaceToken(literalCode + replacementCode);
}
/**
* Starting in the middle of the props object literal, produce an additional
* prop for the children and close the object literal.
*/
processAutomaticChildrenAndEndProps(jsxRole) {
if (jsxRole === JSXRole.StaticChildren) {
this.tokens.appendCode(" children: [");
this.processChildren(false);
this.tokens.appendCode("]}");
} else {
// The parser information tells us whether we will see a real child or if
// all remaining children (if any) will resolve to empty. If there are no
// non-empty children, don't emit a children prop at all, but still
// process children so that we properly transform the code into nothing.
if (jsxRole === JSXRole.OneChild) {
this.tokens.appendCode(" children: ");
}
this.processChildren(false);
this.tokens.appendCode("}");
}
}
/**
* Transform children into a comma-separated list, which will be either
* arguments to createElement or array elements of a children prop.
*/
processChildren(needsInitialComma) {
let needsComma = needsInitialComma;
while (true) {
if (this.tokens.matches2(tt.jsxTagStart, tt.slash)) {
// Closing tag, so no more children.
return;
}
let didEmitElement = false;
if (this.tokens.matches1(tt.braceL)) {
if (this.tokens.matches2(tt.braceL, tt.braceR)) {
// Empty interpolations and comment-only interpolations are allowed
// and don't create an extra child arg.
this.tokens.replaceToken("");
this.tokens.replaceToken("");
} else {
// Interpolated expression.
this.tokens.replaceToken(needsComma ? ", " : "");
this.rootTransformer.processBalancedCode();
this.tokens.replaceToken("");
didEmitElement = true;
}
} else if (this.tokens.matches1(tt.jsxTagStart)) {
// Child JSX element
this.tokens.appendCode(needsComma ? ", " : "");
this.processJSXTag();
didEmitElement = true;
} else if (this.tokens.matches1(tt.jsxText) || this.tokens.matches1(tt.jsxEmptyText)) {
didEmitElement = this.processChildTextElement(needsComma);
} else {
throw new Error("Unexpected token when processing JSX children.");
}
if (didEmitElement) {
needsComma = true;
}
}
}
/**
* Turn a JSX text element into a string literal, or nothing at all if the JSX
* text resolves to the empty string.
*
* Returns true if a string literal is emitted, false otherwise.
*/
processChildTextElement(needsComma) {
const token = this.tokens.currentToken();
const valueCode = this.tokens.code.slice(token.start, token.end);
const replacementCode = formatJSXTextReplacement(valueCode);
const literalCode = formatJSXTextLiteral(valueCode);
if (literalCode === '""') {
this.tokens.replaceToken(replacementCode);
return false;
} else {
this.tokens.replaceToken(`${needsComma ? ", " : ""}${literalCode}${replacementCode}`);
return true;
}
}
getDevSource(elementLocationCode) {
return `{fileName: ${this.getFilenameVarName()}, ${elementLocationCode}}`;
}
getFilenameVarName() {
if (!this.filenameVarName) {
this.filenameVarName = this.nameManager.claimFreeName("_jsxFileName");
}
return this.filenameVarName;
}
}
/**
* Spec for identifiers: https://tc39.github.io/ecma262/#prod-IdentifierStart.
*
* Really only treat anything starting with a-z as tag names. `_`, `$`, `é`
* should be treated as component names
*/
export function startsWithLowerCase(s) {
const firstChar = s.charCodeAt(0);
return firstChar >= charCodes.lowercaseA && firstChar <= charCodes.lowercaseZ;
}
/**
* Turn the given jsxText string into a JS string literal. Leading and trailing
* whitespace on lines is removed, except immediately after the open-tag and
* before the close-tag. Empty lines are completely removed, and spaces are
* added between lines after that.
*
* We use JSON.stringify to introduce escape characters as necessary, and trim
* the start and end of each line and remove blank lines.
*/
function formatJSXTextLiteral(text) {
let result = "";
let whitespace = "";
let isInInitialLineWhitespace = false;
let seenNonWhitespace = false;
for (let i = 0; i < text.length; i++) {
const c = text[i];
if (c === " " || c === "\t" || c === "\r") {
if (!isInInitialLineWhitespace) {
whitespace += c;
}
} else if (c === "\n") {
whitespace = "";
isInInitialLineWhitespace = true;
} else {
if (seenNonWhitespace && isInInitialLineWhitespace) {
result += " ";
}
result += whitespace;
whitespace = "";
if (c === "&") {
const {entity, newI} = processEntity(text, i + 1);
i = newI - 1;
result += entity;
} else {
result += c;
}
seenNonWhitespace = true;
isInInitialLineWhitespace = false;
}
}
if (!isInInitialLineWhitespace) {
result += whitespace;
}
return JSON.stringify(result);
}
/**
* Produce the code that should be printed after the JSX text string literal,
* with most content removed, but all newlines preserved and all spacing at the
* end preserved.
*/
function formatJSXTextReplacement(text) {
let numNewlines = 0;
let numSpaces = 0;
for (const c of text) {
if (c === "\n") {
numNewlines++;
numSpaces = 0;
} else if (c === " ") {
numSpaces++;
}
}
return "\n".repeat(numNewlines) + " ".repeat(numSpaces);
}
/**
* Format a string in the value position of a JSX prop.
*
* Use the same implementation as convertAttribute from
* babel-helper-builder-react-jsx.
*/
function formatJSXStringValueLiteral(text) {
let result = "";
for (let i = 0; i < text.length; i++) {
const c = text[i];
if (c === "\n") {
if (/\s/.test(text[i + 1])) {
result += " ";
while (i < text.length && /\s/.test(text[i + 1])) {
i++;
}
} else {
result += "\n";
}
} else if (c === "&") {
const {entity, newI} = processEntity(text, i + 1);
result += entity;
i = newI - 1;
} else {
result += c;
}
}
return JSON.stringify(result);
}
/**
* Starting at a &, see if there's an HTML entity (specified by name, decimal
* char code, or hex char code) and return it if so.
*
* Modified from jsxReadString in babel-parser.
*/
function processEntity(text, indexAfterAmpersand) {
let str = "";
let count = 0;
let entity;
let i = indexAfterAmpersand;
if (text[i] === "#") {
let radix = 10;
i++;
let numStart;
if (text[i] === "x") {
radix = 16;
i++;
numStart = i;
while (i < text.length && isHexDigit(text.charCodeAt(i))) {
i++;
}
} else {
numStart = i;
while (i < text.length && isDecimalDigit(text.charCodeAt(i))) {
i++;
}
}
if (text[i] === ";") {
const numStr = text.slice(numStart, i);
if (numStr) {
i++;
entity = String.fromCodePoint(parseInt(numStr, radix));
}
}
} else {
while (i < text.length && count++ < 10) {
const ch = text[i];
i++;
if (ch === ";") {
entity = XHTMLEntities.get(str);
break;
}
str += ch;
}
}
if (!entity) {
return {entity: "&", newI: indexAfterAmpersand};
}
return {entity, newI: i};
}
function isDecimalDigit(code) {
return code >= charCodes.digit0 && code <= charCodes.digit9;
}
function isHexDigit(code) {
return (
(code >= charCodes.digit0 && code <= charCodes.digit9) ||
(code >= charCodes.lowercaseA && code <= charCodes.lowercaseF) ||
(code >= charCodes.uppercaseA && code <= charCodes.uppercaseF)
);
}