devsite/node_modules/sucrase/dist/esm/transformers/RootTransformer.js

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2024-07-08 01:49:38 +00:00
import {ContextualKeyword} from "../parser/tokenizer/keywords";
import {TokenType as tt} from "../parser/tokenizer/types";
import getClassInfo, {} from "../util/getClassInfo";
import CJSImportTransformer from "./CJSImportTransformer";
import ESMImportTransformer from "./ESMImportTransformer";
import FlowTransformer from "./FlowTransformer";
import JestHoistTransformer from "./JestHoistTransformer";
import JSXTransformer from "./JSXTransformer";
import NumericSeparatorTransformer from "./NumericSeparatorTransformer";
import OptionalCatchBindingTransformer from "./OptionalCatchBindingTransformer";
import OptionalChainingNullishTransformer from "./OptionalChainingNullishTransformer";
import ReactDisplayNameTransformer from "./ReactDisplayNameTransformer";
import ReactHotLoaderTransformer from "./ReactHotLoaderTransformer";
import TypeScriptTransformer from "./TypeScriptTransformer";
export default class RootTransformer {
__init() {this.transformers = []}
__init2() {this.generatedVariables = []}
constructor(
sucraseContext,
transforms,
enableLegacyBabel5ModuleInterop,
options,
) {;RootTransformer.prototype.__init.call(this);RootTransformer.prototype.__init2.call(this);
this.nameManager = sucraseContext.nameManager;
this.helperManager = sucraseContext.helperManager;
const {tokenProcessor, importProcessor} = sucraseContext;
this.tokens = tokenProcessor;
this.isImportsTransformEnabled = transforms.includes("imports");
this.isReactHotLoaderTransformEnabled = transforms.includes("react-hot-loader");
this.disableESTransforms = Boolean(options.disableESTransforms);
if (!options.disableESTransforms) {
this.transformers.push(
new OptionalChainingNullishTransformer(tokenProcessor, this.nameManager),
);
this.transformers.push(new NumericSeparatorTransformer(tokenProcessor));
this.transformers.push(new OptionalCatchBindingTransformer(tokenProcessor, this.nameManager));
}
if (transforms.includes("jsx")) {
if (options.jsxRuntime !== "preserve") {
this.transformers.push(
new JSXTransformer(this, tokenProcessor, importProcessor, this.nameManager, options),
);
}
this.transformers.push(
new ReactDisplayNameTransformer(this, tokenProcessor, importProcessor, options),
);
}
let reactHotLoaderTransformer = null;
if (transforms.includes("react-hot-loader")) {
if (!options.filePath) {
throw new Error("filePath is required when using the react-hot-loader transform.");
}
reactHotLoaderTransformer = new ReactHotLoaderTransformer(tokenProcessor, options.filePath);
this.transformers.push(reactHotLoaderTransformer);
}
// Note that we always want to enable the imports transformer, even when the import transform
// itself isn't enabled, since we need to do type-only import pruning for both Flow and
// TypeScript.
if (transforms.includes("imports")) {
if (importProcessor === null) {
throw new Error("Expected non-null importProcessor with imports transform enabled.");
}
this.transformers.push(
new CJSImportTransformer(
this,
tokenProcessor,
importProcessor,
this.nameManager,
this.helperManager,
reactHotLoaderTransformer,
enableLegacyBabel5ModuleInterop,
Boolean(options.enableLegacyTypeScriptModuleInterop),
transforms.includes("typescript"),
transforms.includes("flow"),
Boolean(options.preserveDynamicImport),
Boolean(options.keepUnusedImports),
),
);
} else {
this.transformers.push(
new ESMImportTransformer(
tokenProcessor,
this.nameManager,
this.helperManager,
reactHotLoaderTransformer,
transforms.includes("typescript"),
transforms.includes("flow"),
Boolean(options.keepUnusedImports),
options,
),
);
}
if (transforms.includes("flow")) {
this.transformers.push(
new FlowTransformer(this, tokenProcessor, transforms.includes("imports")),
);
}
if (transforms.includes("typescript")) {
this.transformers.push(
new TypeScriptTransformer(this, tokenProcessor, transforms.includes("imports")),
);
}
if (transforms.includes("jest")) {
this.transformers.push(
new JestHoistTransformer(this, tokenProcessor, this.nameManager, importProcessor),
);
}
}
transform() {
this.tokens.reset();
this.processBalancedCode();
const shouldAddUseStrict = this.isImportsTransformEnabled;
// "use strict" always needs to be first, so override the normal transformer order.
let prefix = shouldAddUseStrict ? '"use strict";' : "";
for (const transformer of this.transformers) {
prefix += transformer.getPrefixCode();
}
prefix += this.helperManager.emitHelpers();
prefix += this.generatedVariables.map((v) => ` var ${v};`).join("");
for (const transformer of this.transformers) {
prefix += transformer.getHoistedCode();
}
let suffix = "";
for (const transformer of this.transformers) {
suffix += transformer.getSuffixCode();
}
const result = this.tokens.finish();
let {code} = result;
if (code.startsWith("#!")) {
let newlineIndex = code.indexOf("\n");
if (newlineIndex === -1) {
newlineIndex = code.length;
code += "\n";
}
return {
code: code.slice(0, newlineIndex + 1) + prefix + code.slice(newlineIndex + 1) + suffix,
// The hashbang line has no tokens, so shifting the tokens to account
// for prefix can happen normally.
mappings: this.shiftMappings(result.mappings, prefix.length),
};
} else {
return {
code: prefix + code + suffix,
mappings: this.shiftMappings(result.mappings, prefix.length),
};
}
}
processBalancedCode() {
let braceDepth = 0;
let parenDepth = 0;
while (!this.tokens.isAtEnd()) {
if (this.tokens.matches1(tt.braceL) || this.tokens.matches1(tt.dollarBraceL)) {
braceDepth++;
} else if (this.tokens.matches1(tt.braceR)) {
if (braceDepth === 0) {
return;
}
braceDepth--;
}
if (this.tokens.matches1(tt.parenL)) {
parenDepth++;
} else if (this.tokens.matches1(tt.parenR)) {
if (parenDepth === 0) {
return;
}
parenDepth--;
}
this.processToken();
}
}
processToken() {
if (this.tokens.matches1(tt._class)) {
this.processClass();
return;
}
for (const transformer of this.transformers) {
const wasProcessed = transformer.process();
if (wasProcessed) {
return;
}
}
this.tokens.copyToken();
}
/**
* Skip past a class with a name and return that name.
*/
processNamedClass() {
if (!this.tokens.matches2(tt._class, tt.name)) {
throw new Error("Expected identifier for exported class name.");
}
const name = this.tokens.identifierNameAtIndex(this.tokens.currentIndex() + 1);
this.processClass();
return name;
}
processClass() {
const classInfo = getClassInfo(this, this.tokens, this.nameManager, this.disableESTransforms);
// Both static and instance initializers need a class name to use to invoke the initializer, so
// assign to one if necessary.
const needsCommaExpression =
(classInfo.headerInfo.isExpression || !classInfo.headerInfo.className) &&
classInfo.staticInitializerNames.length + classInfo.instanceInitializerNames.length > 0;
let className = classInfo.headerInfo.className;
if (needsCommaExpression) {
className = this.nameManager.claimFreeName("_class");
this.generatedVariables.push(className);
this.tokens.appendCode(` (${className} =`);
}
const classToken = this.tokens.currentToken();
const contextId = classToken.contextId;
if (contextId == null) {
throw new Error("Expected class to have a context ID.");
}
this.tokens.copyExpectedToken(tt._class);
while (!this.tokens.matchesContextIdAndLabel(tt.braceL, contextId)) {
this.processToken();
}
this.processClassBody(classInfo, className);
const staticInitializerStatements = classInfo.staticInitializerNames.map(
(name) => `${className}.${name}()`,
);
if (needsCommaExpression) {
this.tokens.appendCode(
`, ${staticInitializerStatements.map((s) => `${s}, `).join("")}${className})`,
);
} else if (classInfo.staticInitializerNames.length > 0) {
this.tokens.appendCode(` ${staticInitializerStatements.map((s) => `${s};`).join(" ")}`);
}
}
/**
* We want to just handle class fields in all contexts, since TypeScript supports them. Later,
* when some JS implementations support class fields, this should be made optional.
*/
processClassBody(classInfo, className) {
const {
headerInfo,
constructorInsertPos,
constructorInitializerStatements,
fields,
instanceInitializerNames,
rangesToRemove,
} = classInfo;
let fieldIndex = 0;
let rangeToRemoveIndex = 0;
const classContextId = this.tokens.currentToken().contextId;
if (classContextId == null) {
throw new Error("Expected non-null context ID on class.");
}
this.tokens.copyExpectedToken(tt.braceL);
if (this.isReactHotLoaderTransformEnabled) {
this.tokens.appendCode(
"__reactstandin__regenerateByEval(key, code) {this[key] = eval(code);}",
);
}
const needsConstructorInit =
constructorInitializerStatements.length + instanceInitializerNames.length > 0;
if (constructorInsertPos === null && needsConstructorInit) {
const constructorInitializersCode = this.makeConstructorInitCode(
constructorInitializerStatements,
instanceInitializerNames,
className,
);
if (headerInfo.hasSuperclass) {
const argsName = this.nameManager.claimFreeName("args");
this.tokens.appendCode(
`constructor(...${argsName}) { super(...${argsName}); ${constructorInitializersCode}; }`,
);
} else {
this.tokens.appendCode(`constructor() { ${constructorInitializersCode}; }`);
}
}
while (!this.tokens.matchesContextIdAndLabel(tt.braceR, classContextId)) {
if (fieldIndex < fields.length && this.tokens.currentIndex() === fields[fieldIndex].start) {
let needsCloseBrace = false;
if (this.tokens.matches1(tt.bracketL)) {
this.tokens.copyTokenWithPrefix(`${fields[fieldIndex].initializerName}() {this`);
} else if (this.tokens.matches1(tt.string) || this.tokens.matches1(tt.num)) {
this.tokens.copyTokenWithPrefix(`${fields[fieldIndex].initializerName}() {this[`);
needsCloseBrace = true;
} else {
this.tokens.copyTokenWithPrefix(`${fields[fieldIndex].initializerName}() {this.`);
}
while (this.tokens.currentIndex() < fields[fieldIndex].end) {
if (needsCloseBrace && this.tokens.currentIndex() === fields[fieldIndex].equalsIndex) {
this.tokens.appendCode("]");
}
this.processToken();
}
this.tokens.appendCode("}");
fieldIndex++;
} else if (
rangeToRemoveIndex < rangesToRemove.length &&
this.tokens.currentIndex() >= rangesToRemove[rangeToRemoveIndex].start
) {
if (this.tokens.currentIndex() < rangesToRemove[rangeToRemoveIndex].end) {
this.tokens.removeInitialToken();
}
while (this.tokens.currentIndex() < rangesToRemove[rangeToRemoveIndex].end) {
this.tokens.removeToken();
}
rangeToRemoveIndex++;
} else if (this.tokens.currentIndex() === constructorInsertPos) {
this.tokens.copyToken();
if (needsConstructorInit) {
this.tokens.appendCode(
`;${this.makeConstructorInitCode(
constructorInitializerStatements,
instanceInitializerNames,
className,
)};`,
);
}
this.processToken();
} else {
this.processToken();
}
}
this.tokens.copyExpectedToken(tt.braceR);
}
makeConstructorInitCode(
constructorInitializerStatements,
instanceInitializerNames,
className,
) {
return [
...constructorInitializerStatements,
...instanceInitializerNames.map((name) => `${className}.prototype.${name}.call(this)`),
].join(";");
}
/**
* Normally it's ok to simply remove type tokens, but we need to be more careful when dealing with
* arrow function return types since they can confuse the parser. In that case, we want to move
* the close-paren to the same line as the arrow.
*
* See https://github.com/alangpierce/sucrase/issues/391 for more details.
*/
processPossibleArrowParamEnd() {
if (this.tokens.matches2(tt.parenR, tt.colon) && this.tokens.tokenAtRelativeIndex(1).isType) {
let nextNonTypeIndex = this.tokens.currentIndex() + 1;
// Look ahead to see if this is an arrow function or something else.
while (this.tokens.tokens[nextNonTypeIndex].isType) {
nextNonTypeIndex++;
}
if (this.tokens.matches1AtIndex(nextNonTypeIndex, tt.arrow)) {
this.tokens.removeInitialToken();
while (this.tokens.currentIndex() < nextNonTypeIndex) {
this.tokens.removeToken();
}
this.tokens.replaceTokenTrimmingLeftWhitespace(") =>");
return true;
}
}
return false;
}
/**
* An async arrow function might be of the form:
*
* async <
* T
* >() => {}
*
* in which case, removing the type parameters will cause a syntax error. Detect this case and
* move the open-paren earlier.
*/
processPossibleAsyncArrowWithTypeParams() {
if (
!this.tokens.matchesContextual(ContextualKeyword._async) &&
!this.tokens.matches1(tt._async)
) {
return false;
}
const nextToken = this.tokens.tokenAtRelativeIndex(1);
if (nextToken.type !== tt.lessThan || !nextToken.isType) {
return false;
}
let nextNonTypeIndex = this.tokens.currentIndex() + 1;
// Look ahead to see if this is an arrow function or something else.
while (this.tokens.tokens[nextNonTypeIndex].isType) {
nextNonTypeIndex++;
}
if (this.tokens.matches1AtIndex(nextNonTypeIndex, tt.parenL)) {
this.tokens.replaceToken("async (");
this.tokens.removeInitialToken();
while (this.tokens.currentIndex() < nextNonTypeIndex) {
this.tokens.removeToken();
}
this.tokens.removeToken();
// We ate a ( token, so we need to process the tokens in between and then the ) token so that
// we remain balanced.
this.processBalancedCode();
this.processToken();
return true;
}
return false;
}
processPossibleTypeRange() {
if (this.tokens.currentToken().isType) {
this.tokens.removeInitialToken();
while (this.tokens.currentToken().isType) {
this.tokens.removeToken();
}
return true;
}
return false;
}
shiftMappings(
mappings,
prefixLength,
) {
for (let i = 0; i < mappings.length; i++) {
const mapping = mappings[i];
if (mapping !== undefined) {
mappings[i] = mapping + prefixLength;
}
}
return mappings;
}
}