sprawling-runtime 0.0.10

// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at https://mozilla.org/MPL/2.0/.
// Copyright (c) 2026 2youg1 and the sprawling contributors

//! What a branch inherits: the mother's conversation, rebuilt from her
//! own records, cut at the last line that is a place a conversation can
//! be cut.
//!
//! The ledger is built by a real one (`storage::JsonlLedger`), so the
//! bytes these tests read are the bytes a run writes: the point of
//! rebuilding from records is that they survive a process, and a
//! hand-built payload would not prove that.

#![allow(
    clippy::unwrap_used,
    clippy::expect_used,
    clippy::panic,
    clippy::indexing_slicing,
    clippy::arithmetic_side_effects,
    clippy::wildcard_enum_match_arm,
    reason = "test code"
)]

use kernel::event::record::{
    ModelReturned, RunStarted, SteerReceived, ToolAnswer, ToolCalled, ToolResult,
};
use kernel::{Address, ContentBlock, EventDraft, EventKind, Payload, Role, RunId, Seq, TimeMs};

use super::Inherited;

fn room() -> Address {
    Address::parse("lab/room1").unwrap()
}

/// One line of the mother's conversation, as the turn layer appends it.
pub(super) fn line(kind: EventKind, data: Payload) -> EventDraft {
    EventDraft {
        run: RunId::CITY,
        t: TimeMs::new(0),
        who: "lab/room1".to_owned(),
        addr: Some(room()),
        kind,
        data,
        ig: false,
    }
}

/// A run that made one turn: a task, a reply that asked for a call, the
/// call, and its result.
fn mother() -> Mother {
    verified(mother_drafts())
}

/// A ledger on disk holding `drafts`, and its index.
fn verified(drafts: Vec<EventDraft>) -> Mother {
    let dir = tempfile::tempdir().unwrap();
    let (mut ledger, _) = storage::JsonlLedger::open(dir.path(), TimeMs::new(0)).unwrap();
    ledger.append_all(drafts).unwrap();
    drop(ledger);
    Mother::written(dir)
}

/// A mother's ledger on disk and the index its only writer keeps over it.
pub(super) struct Mother {
    dir: tempfile::TempDir,
    index: storage::LedgerIndex,
}

impl Mother {
    pub(super) fn written(dir: tempfile::TempDir) -> Mother {
        let mut index = storage::LedgerIndex::empty();
        index.refresh(dir.path()).unwrap();
        Mother { dir, index }
    }

    pub(super) fn inherited(&self, at: Seq) -> Result<Inherited, kernel::AxError> {
        super::inherited_indexed(&self.index, self.dir.path(), at)
    }
}

/// The mother's four lines, as drafts.
fn mother_drafts() -> Vec<EventDraft> {
    vec![
        line(
            EventKind::RunStarted,
            Payload::of(&RunStarted {
                task: "measure the meter".to_owned(),
                goal: "a number is written down".to_owned(),
                ..RunStarted::default()
            })
            .unwrap(),
        ),
        line(
            EventKind::ModelReturned,
            Payload::of(&ModelReturned {
                message: kernel::model::message_payload(&[ContentBlock::Text {
                    text: "reading it now".to_owned(),
                }])
                .unwrap(),
                calls: 1,
                usage: None,
                stop: None,
                billed_usd_micros: None,
                first_at: None,
                first_us: None,
                took_us: None,
            })
            .unwrap(),
        ),
        line(
            EventKind::ToolCalled,
            Payload::of(&ToolCalled {
                id: "tu_1".to_owned(),
                name: kernel::ToolName::parse("status").unwrap(),
                args: Payload::empty(),
                subject: None,
                effect: None,
                render: None,
            })
            .unwrap(),
        ),
        line(
            EventKind::ToolResult,
            Payload::of(&ToolResult {
                tool_use_id: "tu_1".to_owned(),
                name: kernel::ToolName::parse("status").unwrap(),
                answer: ToolAnswer::Answered {
                    result: Payload::new(
                        [("said".to_owned(), serde_json::Value::from("42"))]
                            .into_iter()
                            .collect(),
                    )
                    .unwrap(),
                },
                took_us: None,
            })
            .unwrap(),
        ),
    ]
}

/// A mother run with a line of a newer kind inside it: the rebuild skips
/// the line and reaches the conversation the same run holds without it,
/// rather than refusing it.
#[test]
fn a_mother_run_holding_a_line_of_a_newer_kind_rebuilds_without_it() {
    let dir = tempfile::tempdir().unwrap();
    let drafts = mother_drafts();
    let (head, tail) = drafts.split_at(2);
    {
        let (mut ledger, _) = storage::JsonlLedger::open(dir.path(), TimeMs::new(0)).unwrap();
        ledger.append_all(head.to_vec()).unwrap();
    }
    let segment = storage::ledger_segments_at(dir.path())
        .unwrap()
        .pop()
        .unwrap();
    let mut written = std::fs::read(&segment).unwrap();
    let last = written
        .split(|byte| *byte == b'\n')
        .rfind(|line| !line.is_empty())
        .unwrap()
        .to_vec();
    let future = format!(
        "{{\"v\":1,\"run\":{},\"seq\":2,\"prev\":\"{}\",\"t\":0,\"who\":\"city\",\"kind\":\"kind_from_the_future\",\"data\":{{}},\"ig\":true}}\n",
        serde_json::to_string(&RunId::CITY).unwrap(),
        kernel::ledger::chain_hash(&last)
    );
    written.extend_from_slice(future.as_bytes());
    std::fs::write(&segment, written).unwrap();
    {
        let (mut ledger, _) = storage::JsonlLedger::open(dir.path(), TimeMs::new(0)).unwrap();
        ledger.append_all(tail.to_vec()).unwrap();
    }
    let with_newer = Mother::written(dir).inherited(Seq::new(4)).unwrap();
    let without = mother().inherited(Seq::new(3)).unwrap();
    assert_eq!(
        with_newer,
        Inherited {
            at: Seq::new(4),
            ..without
        }
    );
}

/// A steer recorded after the request was assembled reached the mother at
/// the end of the next tool results, and the branch rebuilds it there: the
/// task message she sent stays the bytes she sent.
#[test]
fn a_steer_after_assembly_is_inherited_after_the_results() {
    let mut drafts = mother_drafts();
    drafts.splice(
        1..1,
        [
            line(EventKind::PromptShapeCompared, Payload::empty()),
            line(
                EventKind::SteerReceived,
                Payload::of(&SteerReceived {
                    source: "user".to_owned(),
                    text: "in metres".to_owned(),
                })
                .unwrap(),
            ),
        ],
    );
    let inherited = verified(drafts).inherited(Seq::new(5)).unwrap();

    let mut expected = crate::conversation::Conversation::new();
    expected.push_task_lines(
        "measure the meter",
        "a number is written down",
        crate::conversation::Opening::WithPerson,
        "the User",
    );
    expected.push_assistant(vec![ContentBlock::Text {
        text: "reading it now".to_owned(),
    }]);
    expected.push_tool_results(vec![
        ContentBlock::ToolResult {
            tool_use_id: "tu_1".to_owned(),
            content: "{\"said\":\"42\"}".to_owned(),
            is_error: false,
            attachments: Vec::new(),
        },
        ContentBlock::Text {
            text: "user: in metres".to_owned(),
        },
    ]);
    assert_eq!(inherited.messages, expected.messages().to_vec());
}

/// The rebuild is the mother's own window, folded through the same type
/// the live loop folds through.
#[test]
fn a_branch_inherits_the_mother_window_message_for_message() {
    let inherited = mother().inherited(Seq::new(3)).unwrap();
    assert_eq!(inherited.at, Seq::new(3));

    let mut expected = crate::conversation::Conversation::new();
    expected.push_task_lines(
        "measure the meter",
        "a number is written down",
        crate::conversation::Opening::WithPerson,
        "the User",
    );
    expected.push_assistant(vec![ContentBlock::Text {
        text: "reading it now".to_owned(),
    }]);
    expected.push_tool_results(vec![ContentBlock::ToolResult {
        tool_use_id: "tu_1".to_owned(),
        content: "{\"said\":\"42\"}".to_owned(),
        is_error: false,
        attachments: Vec::new(),
    }]);
    assert_eq!(inherited.messages, expected.messages().to_vec());
    assert_eq!(inherited.messages[0].role, Role::User);
    assert_eq!(inherited.messages[1].role, Role::Assistant);
    assert_eq!(inherited.messages[2].role, Role::User);
}

/// A branch of a branch opened with only its mother's own turns: the
/// conversation the mother had inherited from its own mother was folded
/// into the mother's window but never into a rebuild of it.
#[test]
fn a_branch_of_a_branch_keeps_the_grandmother_conversation() {
    let daughter = RunId::from_bytes([7; 16]);
    let of_daughter = |mut draft: EventDraft| {
        draft.run = daughter;
        draft
    };
    let mut lines = mother_drafts();
    lines.push(of_daughter(line(
        EventKind::RunForked,
        Payload::of(&kernel::event::record::RunForked {
            from: RunId::CITY,
            at_seq: Seq::new(3),
        })
        .unwrap(),
    )));
    lines.push(of_daughter(line(
        EventKind::RunStarted,
        Payload::of(&RunStarted {
            task: "write it down twice".to_owned(),
            goal: "two numbers".to_owned(),
            ..RunStarted::default()
        })
        .unwrap(),
    )));
    lines.push(of_daughter(line(
        EventKind::ModelReturned,
        Payload::of(&ModelReturned {
            message: kernel::model::message_payload(&[ContentBlock::Text {
                text: "written".to_owned(),
            }])
            .unwrap(),
            calls: 0,
            usage: None,
            stop: None,
            billed_usd_micros: None,
            first_at: None,
            first_us: None,
            took_us: None,
        })
        .unwrap(),
    )));
    let history = verified(lines);

    let grandmother = history.inherited(Seq::new(3)).unwrap();
    let mut expected = crate::conversation::Conversation::new();
    expected.push_inherited(&grandmother.messages);
    expected.push_task_lines(
        "write it down twice",
        "two numbers",
        crate::conversation::Opening::WithPerson,
        "the User",
    );
    expected.push_assistant(vec![ContentBlock::Text {
        text: "written".to_owned(),
    }]);
    let granddaughter = history.inherited(Seq::new(6)).unwrap();
    assert_eq!(
        (granddaughter.at, granddaughter.messages),
        (Seq::new(6), expected.messages().to_vec())
    );
}

/// A cut inside a wave of calls moves back to the last line that is a
/// place a conversation can be cut: an assistant message whose tool uses
/// nothing answers is a shape no provider accepts.
#[test]
fn a_cut_inside_a_wave_moves_back_to_the_safe_point() {
    let mother = mother();

    // Line 2 is the call and line 3 its result, so a branch at the call
    // itself ends at the reply that asked for it - and the reply is
    // dropped too, because a call with no answer is half an exchange.
    let at_call = mother.inherited(Seq::new(2)).unwrap();
    assert_eq!(at_call.at, Seq::new(0));
    assert!(
        at_call
            .messages
            .iter()
            .all(|message| message.role != Role::Assistant),
        "the half-answered wave is dropped whole: {:?}",
        at_call.messages
    );

    // A branch at the run's first line inherits the task and nothing
    // else, which is a conversation one message old.
    let at_open = mother.inherited(Seq::new(0)).unwrap();
    assert_eq!(at_open.at, Seq::new(0));
    assert_eq!(at_open.messages.len(), 1);
}

/// A line the history does not hold is refused with the fact that
/// settles it: where the sequence ends.
#[test]
fn a_cut_the_history_does_not_hold_is_refused() {
    let mother = mother();
    let err = mother.inherited(Seq::new(99)).unwrap_err();
    assert_eq!(err.code(), &kernel::AxCode::InvalidArgs);
    assert!(err.recovery().contains("ends at seq 3"), "{err}");
}