047 flow step brace is invocation not constructor

✓ Passing This code compiles and runs correctly.

Code

// PIN: a source-block event invoked at a flow-step must parse as an INVOCATION,
// regardless of whether the brace block spans one line or several.
//
// THE BUG (silent, invisible since 2026-09): the parser decided
// branch-constructor vs source-block-invocation purely by whether the `{ }`
// spanned a newline — single line → branch_constructor, multiline → invocation.
// So `|> render { x: 1 }` (one line) was silently eaten as a branch constructor
// of `setup` — a VOID event with no branches — and compiled clean, exit 0.
//
// DESIRED: `|>` + `name { ... }` is always an invocation (constructions are
// marked with `=>`). Layout is irrelevant. This test pins the single-line case
// to the invocation reading. It is RED until the parser stops guessing by newline.
~event render { source: Source<HTML> }
~event setup {}
~setup() |> render { x: 1 }

input.kz

Flows

flow ~setup click a branch to expand · @labels scroll to their anchor

setup

Expected AST

{
  "module_annotations": [],
  "items": [
    {
      "type": "import_decl",
      "path": "std/compiler",
      "location": {
        "file": "tests/regression/200_COMPILER_FEATURES/210_PARSER/210_047_flow_step_brace_is_invocation_not_constructor/input.kz",
        "line": 2,
        "col": 0
      }
    },
    {
      "type": "host_line",
      "module": "input",
      "location": {
        "file": "tests/regression/200_COMPILER_FEATURES/210_PARSER/210_047_flow_step_brace_is_invocation_not_constructor/input.kz",
        "line": 2,
        "col": 0
      }
    },
    {
      "type": "host_line",
      "module": "input",
      "location": {
        "file": "tests/regression/200_COMPILER_FEATURES/210_PARSER/210_047_flow_step_brace_is_invocation_not_constructor/input.kz",
        "line": 3,
        "col": 0
      }
    },
    {
      "type": "host_line",
      "module": "input",
      "location": {
        "file": "tests/regression/200_COMPILER_FEATURES/210_PARSER/210_047_flow_step_brace_is_invocation_not_constructor/input.kz",
        "line": 4,
        "col": 0
      }
    },
    {
      "type": "host_line",
      "module": "input",
      "location": {
        "file": "tests/regression/200_COMPILER_FEATURES/210_PARSER/210_047_flow_step_brace_is_invocation_not_constructor/input.kz",
        "line": 5,
        "col": 0
      }
    },
    {
      "type": "host_line",
      "module": "input",
      "location": {
        "file": "tests/regression/200_COMPILER_FEATURES/210_PARSER/210_047_flow_step_brace_is_invocation_not_constructor/input.kz",
        "line": 6,
        "col": 0
      }
    },
    {
      "type": "host_line",
      "module": "input",
      "location": {
        "file": "tests/regression/200_COMPILER_FEATURES/210_PARSER/210_047_flow_step_brace_is_invocation_not_constructor/input.kz",
        "line": 7,
        "col": 0
      }
    },
    {
      "type": "host_line",
      "module": "input",
      "location": {
        "file": "tests/regression/200_COMPILER_FEATURES/210_PARSER/210_047_flow_step_brace_is_invocation_not_constructor/input.kz",
        "line": 8,
        "col": 0
      }
    },
    {
      "type": "host_line",
      "module": "input",
      "location": {
        "file": "tests/regression/200_COMPILER_FEATURES/210_PARSER/210_047_flow_step_brace_is_invocation_not_constructor/input.kz",
        "line": 9,
        "col": 0
      }
    },
    {
      "type": "host_line",
      "module": "input",
      "location": {
        "file": "tests/regression/200_COMPILER_FEATURES/210_PARSER/210_047_flow_step_brace_is_invocation_not_constructor/input.kz",
        "line": 10,
        "col": 0
      }
    },
    {
      "type": "host_line",
      "module": "input",
      "location": {
        "file": "tests/regression/200_COMPILER_FEATURES/210_PARSER/210_047_flow_step_brace_is_invocation_not_constructor/input.kz",
        "line": 11,
        "col": 0
      }
    },
    {
      "type": "host_line",
      "module": "input",
      "location": {
        "file": "tests/regression/200_COMPILER_FEATURES/210_PARSER/210_047_flow_step_brace_is_invocation_not_constructor/input.kz",
        "line": 12,
        "col": 0
      }
    },
    {
      "type": "host_line",
      "module": "input",
      "location": {
        "file": "tests/regression/200_COMPILER_FEATURES/210_PARSER/210_047_flow_step_brace_is_invocation_not_constructor/input.kz",
        "line": 13,
        "col": 0
      }
    },
    {
      "type": "event_decl",
      "name": "render",
      "path": [
        "render"
      ],
      "module": "input",
      "input": {
        "fields": [
          {
            "name": "source",
            "type": "Source<HTML>",
            "is_source": true,
            "is_file": false,
            "is_embed_file": false,
            "is_expression": false,
            "is_invocation_meta": false,
            "phantom": null
          }
        ]
      },
      "branches": [],
      "location": {
        "file": "tests/regression/200_COMPILER_FEATURES/210_PARSER/210_047_flow_step_brace_is_invocation_not_constructor/input.kz",
        "line": 15,
        "col": 0
      }
    },
    {
      "type": "event_decl",
      "name": "setup",
      "path": [
        "setup"
      ],
      "module": "input",
      "input": {
        "fields": []
      },
      "branches": [],
      "location": {
        "file": "tests/regression/200_COMPILER_FEATURES/210_PARSER/210_047_flow_step_brace_is_invocation_not_constructor/input.kz",
        "line": 16,
        "col": 0
      }
    },
    {
      "type": "flow",
      "invocation": {
        "event": [
          "setup"
        ],
        "args": [],
        "variant": null
      },
      "continuations": [
        {
          "branch": "",
          "kind": "terminal",
          "is_catchall": false,
          "binding": null,
          "binding_type": "branch_payload",
          "condition": null,
          "step": {
            "type": "invocation",
            "invocation": {
              "event": [
                "render"
              ],
              "args": [
                {
                  "name": "source",
                  "value": "x: 1",
                  "source_value": {
                    "text": "x: 1",
                    "location": {
                      "file": "tests/regression/200_COMPILER_FEATURES/210_PARSER/210_047_flow_step_brace_is_invocation_not_constructor/input.kz",
                      "line": 17,
                      "col": 0
                    },
                    "scope": {
                      "bindings": []
                    },
                    "phantom_type": null
                  }
                }
              ],
              "variant": null
            }
          },
          "continuations": []
        }
      ],
      "pre_label": null,
      "impl_of": null,
      "location": {
        "file": "tests/regression/200_COMPILER_FEATURES/210_PARSER/210_047_flow_step_brace_is_invocation_not_constructor/input.kz",
        "line": 16,
        "col": 0
      }
    }
  ]
}

Test Configuration

PARSER_TEST

← 046 implicit expression with semicolon 048 loop unhandled branch →