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feat: anonymous default exports #801

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Merged
basmasking merged 3 commits into from
Jul 25, 2026
Merged

feat: anonymous default exports #801

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e77e7f9
#799: implemented anonymous support
petermasking Jul 23, 2026
90772b5
#799: boyscout - added additional keywords
petermasking Jul 23, 2026
5c31b73
#799: fixed tests
petermasking Jul 25, 2026
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22 changes: 21 additions & 1 deletion packages/analysis/src/static/Parser.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -30,6 +30,7 @@ import Lexer from './Lexer';
import Coder from './Coder';

const DEFAULT_IDENTIFIER = 'default';
const EXPORTED_PREFIX = '$_EXPORT';

export default class Parser
{
Expand Down Expand Up @@ -384,7 +385,7 @@ export default class Parser
{
// Default exports of values need to move to their own declaration

const identifier = `$_EXPORT_${token.start}_${token.end}`;
const identifier = `${EXPORTED_PREFIX}_${token.start}_${token.end}`;

tokenList.insert(
new Token(TokenType.KEYWORD, Keyword.CONST, 0, 0),
Expand All @@ -405,6 +406,25 @@ export default class Parser
{
token = tokenList.step(); // Read away the declaration keyword
stepSize++;

if (token.hasValue(Indicator.GENERATOR))
{
token = tokenList.step(); // Read away the generator indicator
stepSize++;
}
}

if (token.hasValue(Keyword.EXTENDS)
|| token.hasValue(Group.OPEN)
|| token.hasValue(Scope.OPEN))
{
// Anonymous functions and class need an identifier

const identifier = `${EXPORTED_PREFIX}_${token.start}_${token.end}`;

tokenList.insert(new Token(TokenType.IDENTIFIER, identifier, 0, 0));
Comment on lines +417 to +425

@coderabbitai coderabbitai Bot Jul 25, 2026

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🎯 Functional Correctness | 🟠 Major | ⚡ Quick win

Restrict synthetic names to declaration exports.

Lines 417-425 also match non-declaration expressions such as export default { value: 1 } and export default async () => 1. They receive an exported $_EXPORT_* name, but no corresponding declaration is inserted, leaving resolution with a nonexistent FQN. Gate this branch on having consumed a function or class declaration; route expression forms through the value-rehoming path instead.

Proposed fix 
+        let hasDeclarationKeyword = false;
+
         if (isDeclaration(token.value))
         {
+            hasDeclarationKeyword = true;
             token = tokenList.step(); // Read away the declaration keyword
             stepSize++;
         }

-        if (token.hasValue(Keyword.EXTENDS)
+        if (hasDeclarationKeyword
+         && (token.hasValue(Keyword.EXTENDS)
          || token.hasValue(Group.OPEN)
-         || token.hasValue(Scope.OPEN))
+         || token.hasValue(Scope.OPEN)))
📝 Committable suggestion

‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.

Suggested change
if (token.hasValue(Keyword.EXTENDS)
|| token.hasValue(Group.OPEN)
|| token.hasValue(Scope.OPEN))
{
// Anonymous functions and class need an identifier
const identifier = `${EXPORTED_PREFIX}_${token.start}_${token.end}`;
tokenList.insert(new Token(TokenType.IDENTIFIER, identifier, 0, 0));
let hasDeclarationKeyword = false;
if (isDeclaration(token.value))
{
hasDeclarationKeyword = true;
token = tokenList.step(); // Read away the declaration keyword
stepSize++;
}
if (hasDeclarationKeyword
&& (token.hasValue(Keyword.EXTENDS)
|| token.hasValue(Group.OPEN)
|| token.hasValue(Scope.OPEN)))
{
// Anonymous functions and class need an identifier
const identifier = `${EXPORTED_PREFIX}_${token.start}_${token.end}`;
tokenList.insert(new Token(TokenType.IDENTIFIER, identifier, 0, 0));
🤖 Prompt for AI Agents 
Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@packages/analysis/src/static/Parser.ts` around lines 417 - 425, Restrict the
synthetic identifier insertion in the export-handling branch to cases where the
parser has consumed a function or class declaration. Ensure expression exports
such as object literals and arrow functions bypass this branch and use the
existing value-rehoming path, while preserving synthetic names for anonymous
function and class declarations.


token = tokenList.current;
}

const identifier = this.#isIdentifier(token) ? token.value : '';
Expand Down
6 changes: 5 additions & 1 deletion packages/analysis/src/static/definitions/Keyword.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -50,7 +50,11 @@ const Keyword =
THROW: 'throw',
TRY: 'try',
CATCH: 'catch',
FINALLY: 'finally'
FINALLY: 'finally',

// TYPE CHECKING
TYPEOF: 'typeof',
INSTANCEOF: 'instanceof'
};

const Keywords = Object.values(Keyword);
Expand Down
4 changes: 2 additions & 2 deletions packages/analysis/test/static/Parser.spec.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -350,7 +350,7 @@ describe('Parser', () =>
expect(exported.from).toBeUndefined();

const member = exported.members[0];
expect(member.identifier).toEqual('');
expect(member.identifier).toEqual('$_EXPORT_23_23');
expect(member.alias).toEqual('default');

const declaration = module.statements[1] as ESFunction;
Expand All @@ -368,7 +368,7 @@ describe('Parser', () =>
expect(exported.from).toBeUndefined();

const member = exported.members[0];
expect(member.identifier).toEqual('');
expect(member.identifier).toEqual('$_EXPORT_21_21');
expect(member.alias).toEqual('default');

const declaration = module.statements[1] as ESClass;
Expand Down
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