shrimp/src/parser/tests/exceptions.test.ts

import { expect, describe, test } from 'bun:test'

import '../shrimp.grammar' // Importing this so changes cause it to retest!

describe('try/catch/finally/throw', () => {
  test('parses try with catch', () => {
    expect(`try:
      risky-operation
    catch err:
      handle-error err
    end`).toMatchTree(`
      TryExpr
        keyword try
        colon :
        TryBlock
          FunctionCallOrIdentifier
            Identifier risky-operation
        CatchExpr
          keyword catch
          Identifier err
          colon :
          TryBlock
            FunctionCall
              Identifier handle-error
              PositionalArg
                Identifier err
        keyword end
    `)
  })

  test('parses try with finally', () => {
    expect(`try:
      do-work
    finally:
      cleanup
    end`).toMatchTree(`
      TryExpr
        keyword try
        colon :
        TryBlock
          FunctionCallOrIdentifier
            Identifier do-work
        FinallyExpr
          keyword finally
          colon :
          TryBlock
            FunctionCallOrIdentifier
              Identifier cleanup
        keyword end
    `)
  })

  test('parses try with catch and finally', () => {
    expect(`try:
      risky-operation
    catch err:
      handle-error err
    finally:
      cleanup
    end`).toMatchTree(`
      TryExpr
        keyword try
        colon :
        TryBlock
          FunctionCallOrIdentifier
            Identifier risky-operation
        CatchExpr
          keyword catch
          Identifier err
          colon :
          TryBlock
            FunctionCall
              Identifier handle-error
              PositionalArg
                Identifier err
        FinallyExpr
          keyword finally
          colon :
          TryBlock
            FunctionCallOrIdentifier
              Identifier cleanup
        keyword end
    `)
  })

  test('parses single-line try with catch', () => {
    expect('result = try: parse-number input catch err: 0 end').toMatchTree(`
      Assign
        AssignableIdentifier result
        Eq =
        TryExpr
          keyword try
          colon :
          FunctionCall
            Identifier parse-number
            PositionalArg
              Identifier input
          CatchExpr
            keyword catch
            Identifier err
            colon :
            Number 0
          keyword end
    `)
  })

  test('parses single-line try with finally', () => {
    expect('try: work catch err: 0 finally: cleanup end').toMatchTree(`
      TryExpr
        keyword try
        colon :
        FunctionCallOrIdentifier
          Identifier work
        CatchExpr
          keyword catch
          Identifier err
          colon :
          Number 0
        FinallyExpr
          keyword finally
          colon :
          FunctionCallOrIdentifier
            Identifier cleanup
        keyword end
    `)
  })

  test('parses throw statement with string', () => {
    expect("throw 'error message'").toMatchTree(`
      Throw
        keyword throw
        String
          StringFragment error message
    `)
  })

  test('parses throw statement with identifier', () => {
    expect('throw error-object').toMatchTree(`
      Throw
        keyword throw
        Identifier error-object
    `)
  })

  test('parses throw statement with dict', () => {
    expect('throw [type=validation-error message=failed]').toMatchTree(`
      Throw
        keyword throw
        Dict
          NamedArg
            NamedArgPrefix type=
            Identifier validation-error
          NamedArg
            NamedArgPrefix message=
            Identifier failed
    `)
  })

  test('does not parse identifiers that start with try', () => {
    expect('trying = try: work catch err: 0 end').toMatchTree(`
      Assign
        AssignableIdentifier trying
        Eq =
        TryExpr
          keyword try
          colon :
          FunctionCallOrIdentifier
            Identifier work
          CatchExpr
            keyword catch
            Identifier err
            colon :
            Number 0
          keyword end
    `)
  })
})

describe('function-level exception handling', () => {
  test('parses function with catch', () => {
    expect(`read-file = do path:
      read-data path
    catch e:
      empty-string
    end`).toMatchTree(`
      Assign
        AssignableIdentifier read-file
        Eq =
        FunctionDef
          Do do
          Params
            Identifier path
          colon :
          FunctionCall
            Identifier read-data
            PositionalArg
              Identifier path
          CatchExpr
            keyword catch
            Identifier e
            colon :
            TryBlock
              FunctionCallOrIdentifier
                Identifier empty-string
          keyword end
    `)
  })

  test('parses function with finally', () => {
    expect(`cleanup-task = do x:
      do-work x
    finally:
      close-resources
    end`).toMatchTree(`
      Assign
        AssignableIdentifier cleanup-task
        Eq =
        FunctionDef
          Do do
          Params
            Identifier x
          colon :
          FunctionCall
            Identifier do-work
            PositionalArg
              Identifier x
          FinallyExpr
            keyword finally
            colon :
            TryBlock
              FunctionCallOrIdentifier
                Identifier close-resources
          keyword end
    `)
  })

  test('parses function with catch and finally', () => {
    expect(`safe-operation = do x:
      risky-work x
    catch err:
      log err
      default-value
    finally:
      cleanup
    end`).toMatchTree(`
      Assign
        AssignableIdentifier safe-operation
        Eq =
        FunctionDef
          Do do
          Params
            Identifier x
          colon :
          FunctionCall
            Identifier risky-work
            PositionalArg
              Identifier x
          CatchExpr
            keyword catch
            Identifier err
            colon :
            TryBlock
              FunctionCall
                Identifier log
                PositionalArg
                  Identifier err
              FunctionCallOrIdentifier
                Identifier default-value
          FinallyExpr
            keyword finally
            colon :
            TryBlock
              FunctionCallOrIdentifier
                Identifier cleanup
          keyword end
    `)
  })
})