import * as _acorn from "acorn";
const leftCurlyBrace = "{".charCodeAt(0);
const space = " ".charCodeAt(0);
const keyword = "assert";
const FUNC_STATEMENT = 1, FUNC_HANGING_STATEMENT = 2, FUNC_NULLABLE_ID = 4
export function importAssertions(Parser) {
// Use supplied version acorn version if present, to avoid
// reference mismatches due to different acorn versions. This
// allows this plugin to be used with Rollup which supplies
// its own internal version of acorn and thereby sidesteps
// the package manager.
const acorn = Parser.acorn || _acorn;
const { tokTypes: tt, TokenType } = acorn;
return class extends Parser {
constructor(...args) {
super(...args);
this.assertToken = new TokenType(keyword);
}
_codeAt(i) {
return this.input.charCodeAt(i);
}
_eat(t) {
if (this.type !== t) {
this.unexpected();
}
this.next();
}
readToken(code) {
let i = 0;
for (; i < keyword.length; i++) {
if (this._codeAt(this.pos + i) !== keyword.charCodeAt(i)) {
return super.readToken(code);
}
}
// ensure that the keyword is at the correct location
// ie `assert{...` or `assert {...`
for (;; i++) {
if (this._codeAt(this.pos + i) === leftCurlyBrace) {
// Found '{'
break;
} else if (this._codeAt(this.pos + i) === space) {
// white space is allowed between `assert` and `{`, so continue.
continue;
} else {
return super.readToken(code);
}
}
// If we're inside a dynamic import expression we'll parse
// the `assert` keyword as a standard object property name
// ie `import(""./foo.json", { assert: { type: "json" } })`
if (this.type.label === "{") {
return super.readToken(code);
}
this.pos += keyword.length;
return this.finishToken(this.assertToken);
}
parseDynamicImport(node) {
this.next(); // skip `(`
// Parse node.source.
node.source = this.parseMaybeAssign();
if (this.eat(tt.comma)) {
const obj = this.parseObj(false);
node.arguments = [obj];
}
this._eat(tt.parenR);
return this.finishNode(node, "ImportExpression");
}
// ported from acorn/src/statement.js pp.parseExport
parseExport(node, exports) {
this.next();
// export * from '...'
if (this.eat(tt.star)) {
if (this.options.ecmaVersion >= 11) {
if (this.eatContextual("as")) {
node.exported = this.parseIdent(true);
this.checkExport(exports, node.exported.name, this.lastTokStart);
} else {
node.exported = null;
}
}
this.expectContextual("from");
if (this.type !== tt.string) { this.unexpected(); }
node.source = this.parseExprAtom();
if (this.type === this.assertToken || this.type === tt._with) {
this.next();
const assertions = this.parseImportAssertions();
if (assertions) {
node.assertions = assertions;
}
}
this.semicolon();
return this.finishNode(node, "ExportAllDeclaration")
}
if (this.eat(tt._default)) { // export default ...
this.checkExport(exports, "default", this.lastTokStart);
var isAsync;
if (this.type === tt._function || (isAsync = this.isAsyncFunction())) {
var fNode = this.startNode();
this.next();
if (isAsync) { this.next(); }
node.declaration = this.parseFunction(fNode, FUNC_STATEMENT | FUNC_NULLABLE_ID, false, isAsync);
} else if (this.type === tt._class) {
var cNode = this.startNode();
node.declaration = this.parseClass(cNode, "nullableID");
} else {
node.declaration = this.parseMaybeAssign();
this.semicolon();
}
return this.finishNode(node, "ExportDefaultDeclaration")
}
// export var|const|let|function|class ...
if (this.shouldParseExportStatement()) {
node.declaration = this.parseStatement(null);
if (node.declaration.type === "VariableDeclaration")
{ this.checkVariableExport(exports, node.declaration.declarations); }
else
{ this.checkExport(exports, node.declaration.id.name, node.declaration.id.start); }
node.specifiers = [];
node.source = null;
} else { // export { x, y as z } [from '...']
node.declaration = null;
node.specifiers = this.parseExportSpecifiers(exports);
if (this.eatContextual("from")) {
if (this.type !== tt.string) { this.unexpected(); }
node.source = this.parseExprAtom();
if (this.type === this.assertToken || this.type === tt._with) {
this.next();
const assertions = this.parseImportAssertions();
if (assertions) {
node.assertions = assertions;
}
}
} else {
for (var i = 0, list = node.specifiers; i < list.length; i += 1) {
// check for keywords used as local names
var spec = list[i];
this.checkUnreserved(spec.local);
// check if export is defined
this.checkLocalExport(spec.local);
}
node.source = null;
}
this.semicolon();
}
return this.finishNode(node, "ExportNamedDeclaration")
}
parseImport(node) {
this.next();
// import '...'
if (this.type === tt.string) {
node.specifiers = [];
node.source = this.parseExprAtom();
} else {
node.specifiers = this.parseImportSpecifiers();
this.expectContextual("from");
node.source =
this.type === tt.string ? this.parseExprAtom() : this.unexpected();
}
if (this.type === this.assertToken || this.type == tt._with) {
this.next();
const assertions = this.parseImportAssertions();
if (assertions) {
node.assertions = assertions;
}
}
this.semicolon();
return this.finishNode(node, "ImportDeclaration");
}
parseImportAssertions() {
this._eat(tt.braceL);
const attrs = this.parseAssertEntries();
this._eat(tt.braceR);
return attrs;
}
parseAssertEntries() {
const attrs = [];
const attrNames = new Set();
do {
if (this.type === tt.braceR) {
break;
}
const node = this.startNode();
// parse AssertionKey : IdentifierName, StringLiteral
let assertionKeyNode;
if (this.type === tt.string) {
assertionKeyNode = this.parseLiteral(this.value);
} else {
assertionKeyNode = this.parseIdent(true);
}
this.next();
node.key = assertionKeyNode;
// check if we already have an entry for an attribute
// if a duplicate entry is found, throw an error
// for now this logic will come into play only when someone declares `type` twice
if (attrNames.has(node.key.name)) {
this.raise(this.pos, "Duplicated key in assertions");
}
attrNames.add(node.key.name);
if (this.type !== tt.string) {
this.raise(
this.pos,
"Only string is supported as an assertion value"
);
}
node.value = this.parseLiteral(this.value);
attrs.push(this.finishNode(node, "ImportAttribute"));
} while (this.eat(tt.comma));
return attrs;
}
};
}