throw error when parse try catch block on parseExpressionAt

[himself65]

related issue nodejs/node#30872

const Acorn = require('acorn')
const Parser = Acorn.Parser
const parseExpressionAt = Parser.parseExpressionAt.bind(Parser)
const str = 'try {         assert(condition, message)\n' +
  '  } catch (e) {\n' +
  '    throw e\n' +
  '  }\n' +
  '\n' +
  '// Now run tests\n' +
  '\n' +
  'console.log(\'Call assert proxy with slightly minified whitespace\')\n' +
  'try {\n' +
  '  assertProxySlightlyMinified(0)\n' +
  '  console.error(`assertProxySlightlyMinified(0); failed to cause an exception`)\n' +
  '} catch (e) {\n' +
  '  console.log(`assertProxySlightlyMinified(0); generated exception: ${e}`)\n' +
  '}\n' +
  '\n' +
  'console.log(\'Finished tests\')'
const res = Parser.parseExpressionAt(str, 0)
console.log(res)

C:\Users\Himself65\Desktop\github\test>node index.js
C:\Users\Himself65\Desktop\github\test\node_modules\acorn\dist\acorn.js:2838
    throw err
    ^

SyntaxError: Unexpected token (1:0)
    at Parser.pp$4.raise (C:\Users\Himself65\Desktop\github\test\node_modules\?[4macorn?[24m\dist\acorn.js:2836:15)
    at Parser.pp.unexpected (C:\Users\Himself65\Desktop\github\test\node_modules\?[4macorn?[24m\dist\acorn.js:689:10)
    at Parser.pp$3.parseExprAtom (C:\Users\Himself65\Desktop\github\test\node_modules\?[4macorn?[24m\dist\acorn.js:2260:12)
    at Parser.pp$3.parseExprSubscripts (C:\Users\Himself65\Desktop\github\test\node_modules\?[4macorn?[24m\dist\acorn.js:2089:21)
    at Parser.pp$3.parseMaybeUnary (C:\Users\Himself65\Desktop\github\test\node_modules\?[4macorn?[24m\dist\acorn.js:2066:19)
    at Parser.pp$3.parseExprOps (C:\Users\Himself65\Desktop\github\test\node_modules\?[4macorn?[24m\dist\acorn.js:2010:21)
    at Parser.pp$3.parseMaybeConditional (C:\Users\Himself65\Desktop\github\test\node_modules\?[4macorn?[24m\dist\acorn.js:1993:21)
    at Parser.pp$3.parseMaybeAssign (C:\Users\Himself65\Desktop\github\test\node_modules\?[4macorn?[24m\dist\acorn.js:1968:21)
    at Parser.pp$3.parseExpression (C:\Users\Himself65\Desktop\github\test\node_modules\?[4macorn?[24m\dist\acorn.js:1933:21)
    at Function.parseExpressionAt (C:\Users\Himself65\Desktop\github\test\node_modules\?[4macorn?[24m\dist\acorn.js:582:19) {
  pos: ?[33m0?[39m,
  loc: Position { line: ?[33m1?[39m, column: ?[33m0?[39m },
  raisedAt: ?[33m3?[39m
}

---

but it success when remove try {

const Acorn = require('acorn')
const Parser = Acorn.Parser
const parseExpressionAt = Parser.parseExpressionAt.bind(Parser)
const str = '        assert(condition, message)\n' +
  '  } catch (e) {\n' +
  '    throw e\n' +
  '  }\n' +
  '\n' +
  '// Now run tests\n' +
  '\n' +
  'console.log(\'Call assert proxy with slightly minified whitespace\')\n' +
  'try {\n' +
  '  assertProxySlightlyMinified(0)\n' +
  '  console.error(`assertProxySlightlyMinified(0); failed to cause an exception`)\n' +
  '} catch (e) {\n' +
  '  console.log(`assertProxySlightlyMinified(0); generated exception: ${e}`)\n' +
  '}\n' +
  '\n' +
  'console.log(\'Finished tests\')'
const res = Parser.parseExpressionAt(str, 0)
console.log(res)

C:\Users\Himself65\Desktop\github\test>node index.js
Node {
  type: 'CallExpression',
  start: 8,
  end: 34,
  callee: Node { type: 'Identifier', start: 8, end: 14, name: 'assert' },
  arguments: [
    Node { type: 'Identifier', start: 15, end: 24, name: 'condition' },
    Node { type: 'Identifier', start: 26, end: 33, name: 'message' }
  ]
}

[mysticatea]

I think that it's correct behavior. Because TryStatement is a statement rather than an expression, and parseExpressionAt method parses an expression.

[marijnh]

Agreed, this is working as documented.

[himself65]

thanks for helping