transcribe-cpp 0.4.0

//! `serde` feature: derive coverage plus the crate's custom serde behavior
//! (NaN confidences, sparse-document defaults).

#![cfg(feature = "serde")]

use transcribe_cpp::{
    Backend, Capabilities, CommitPolicy, DeviceType, Diarize, DiarizeExtension, DiarizeInfo,
    DiarizeOptions, DiarizeSessionOptions, ExtSlot, Feature, Itn, KvType, LangIdCandidate,
    LangIdInfo, LangIdOptions, LangIdResult, LangIdSessionOptions, MoonshineStreamingOptions,
    ParakeetBufferedStreamOptions, ParakeetStreamOptions, Pnc, Role, Roles, RunExtension,
    RunOptions, Segment, SessionLimits, SessionOptions, SortformerDiarizeOptions, SortformerPreset,
    SpeakerSegment, StreamExtension, StreamOptions, StreamState, StreamText, StreamUpdate, Task,
    TimestampKind, Timings, Token, Transcript, VadInfo, VadOptions, VadResult, VadSegment,
    VadSessionOptions, VoxtralRealtimeStreamOptions, WhisperRunOptions, Word,
};

fn assert_serde<T: serde::Serialize + serde::de::DeserializeOwned>() {}

/// Fails to compile if any plain-data type loses its derives.
#[test]
fn plain_data_types_are_serializable() {
    // Options.
    assert_serde::<RunOptions>();
    assert_serde::<StreamOptions>();
    assert_serde::<SessionOptions>();
    assert_serde::<RunExtension>();
    assert_serde::<StreamExtension>();
    assert_serde::<WhisperRunOptions>();
    assert_serde::<MoonshineStreamingOptions>();
    assert_serde::<ParakeetStreamOptions>();
    assert_serde::<ParakeetBufferedStreamOptions>();
    assert_serde::<VoxtralRealtimeStreamOptions>();
    assert_serde::<SortformerPreset>();
    assert_serde::<DiarizeOptions>();
    assert_serde::<DiarizeSessionOptions>();
    assert_serde::<DiarizeExtension>();
    assert_serde::<SortformerDiarizeOptions>();
    assert_serde::<LangIdSessionOptions>();
    assert_serde::<LangIdOptions>();
    assert_serde::<VadSessionOptions>();
    assert_serde::<VadOptions>();
    // Results.
    assert_serde::<DiarizeInfo>();
    assert_serde::<LangIdInfo>();
    assert_serde::<VadInfo>();
    assert_serde::<Transcript>();
    assert_serde::<Segment>();
    assert_serde::<SpeakerSegment>();
    assert_serde::<Word>();
    assert_serde::<Token>();
    assert_serde::<Timings>();
    assert_serde::<StreamUpdate>();
    assert_serde::<StreamText>();
    assert_serde::<Capabilities>();
    assert_serde::<SessionLimits>();
    assert_serde::<LangIdResult>();
    assert_serde::<LangIdCandidate>();
    assert_serde::<VadResult>();
    assert_serde::<VadSegment>();
    // Enums.
    assert_serde::<Task>();
    assert_serde::<TimestampKind>();
    assert_serde::<KvType>();
    assert_serde::<Pnc>();
    assert_serde::<Itn>();
    assert_serde::<Diarize>();
    assert_serde::<Backend>();
    assert_serde::<Feature>();
    assert_serde::<CommitPolicy>();
    assert_serde::<StreamState>();
    assert_serde::<DeviceType>();
    assert_serde::<ExtSlot>();
    assert_serde::<Role>();
    assert_serde::<Roles>();
}

fn nan_transcript() -> Transcript {
    Transcript {
        text: "and so".into(),
        speaker_segments: vec![SpeakerSegment {
            t1_ms: 900,
            speaker_id: 1,
            p: f32::NAN,
            ..Default::default()
        }],
        tokens: vec![
            Token {
                id: 42,
                p: f32::NAN,
                text: " and".into(),
                ..Default::default()
            },
            Token {
                id: 43,
                p: 0.75,
                text: " so".into(),
                ..Default::default()
            },
        ],
        ..Default::default()
    }
}

/// NaN != NaN, so compare by postcard bytes.
fn same_transcript(a: &Transcript, b: &Transcript) -> bool {
    postcard::to_allocvec(a).unwrap() == postcard::to_allocvec(b).unwrap()
}

#[test]
fn nan_confidence_round_trips() {
    let original = nan_transcript();

    let json = serde_json::to_string(&original).unwrap();
    assert!(
        json.contains("\"p\":null"),
        "NaN should encode as null: {json}"
    );
    let from_json: Transcript = serde_json::from_str(&json).unwrap();
    assert!(from_json.tokens[0].p.is_nan());
    assert!(from_json.speaker_segments[0].p.is_nan());
    assert_eq!(from_json.tokens[1].p, 0.75);
    assert!(same_transcript(&from_json, &original), "json");

    let bytes = postcard::to_allocvec(&original).unwrap();
    let from_postcard: Transcript = postcard::from_bytes(&bytes).unwrap();
    assert!(from_postcard.tokens[0].p.is_nan());
    assert!(from_postcard.speaker_segments[0].p.is_nan());
    assert!(same_transcript(&from_postcard, &original), "postcard");
}

#[test]
fn missing_fields_take_defaults() {
    // `RunOptions::default()` is hand-written; its -1 sentinel must survive.
    let run: RunOptions = serde_json::from_str(r#"{"language":"fr"}"#).unwrap();
    assert_eq!(run.spec_k_drafts, -1);
    assert_eq!(
        run,
        RunOptions {
            language: Some("fr".into()),
            ..Default::default()
        }
    );

    let token: Token = serde_json::from_str(r#"{"id":5}"#).unwrap();
    assert_eq!(token.id, 5);
    assert!(token.p.is_nan(), "missing p decoded as {}", token.p);
    let speaker: SpeakerSegment = serde_json::from_str(r#"{"speaker_id":2}"#).unwrap();
    assert!(speaker.p.is_nan(), "missing p decoded as {}", speaker.p);

    let langid: LangIdResult = serde_json::from_str(r#"{"allowed_mass":0.5}"#).unwrap();
    assert_eq!(langid.allowed_mass, 0.5);
    assert!(langid.candidates.is_empty());
    let candidate: LangIdCandidate = serde_json::from_str(r#"{"code":"en"}"#).unwrap();
    assert_eq!(candidate.code, "en");
    assert_eq!(candidate.p, 0.0);

    // `VadOptions::default()` is hand-written; the C defaults must survive.
    let vad: VadOptions = serde_json::from_str(r#"{"threshold":0.6}"#).unwrap();
    assert_eq!(
        vad,
        VadOptions {
            threshold: 0.6,
            ..Default::default()
        }
    );
    assert_eq!((vad.neg_threshold, vad.min_speech_ms), (-1.0, 250));
}

mod errors {
    use transcribe_cpp::{Error, ErrorKind, ErrorReport, Transcript};

    fn json(err: &Error) -> serde_json::Value {
        serde_json::to_value(err).unwrap()
    }

    #[test]
    fn error_serializes_kind_message_status() {
        let err = Error::ModelFileNotFound("load x.gguf: file not found (status 3)".into());
        let v = json(&err);
        assert_eq!(v["kind"], "model_file_not_found");
        assert_eq!(v["message"], err.to_string());
        assert_eq!(v["status"], err.raw_status());
        assert!(v["partial"].is_null(), "no partial expected: {v}");
    }

    #[test]
    fn rust_side_errors_serialize_with_status_zero() {
        let nul: Error = std::ffi::CString::new("a\0b").unwrap_err().into();
        let v = json(&nul);
        assert_eq!(v["kind"], "nul");
        assert_eq!(v["status"], 0);

        let busy = json(&Error::Busy("stream active".into()));
        assert_eq!(busy["kind"], "busy");
        assert_eq!(busy["status"], 0);
    }

    #[test]
    fn partial_transcript_round_trips_through_report() {
        let partial = Transcript {
            text: "and so my fellow".into(),
            ..Default::default()
        };
        let err = Error::Aborted {
            message: "run aborted".into(),
            partial: Some(Box::new(partial.clone())),
        };
        let wire = serde_json::to_string(&err).unwrap();
        let report: ErrorReport = serde_json::from_str(&wire).unwrap();
        assert_eq!(report.kind, ErrorKind::Aborted);
        assert_eq!(report.message, err.to_string());
        assert_eq!(report.status, err.raw_status());
        assert_eq!(report.partial.as_ref(), Some(&partial));
        // Serializing the Error and its report produce the same document.
        assert_eq!(
            serde_json::to_string(&ErrorReport::from(&err)).unwrap(),
            wire
        );
    }

    #[test]
    fn unknown_kind_deserializes_as_other() {
        let report: ErrorReport =
            serde_json::from_str(r#"{"kind":"from_the_future","message":"m"}"#).unwrap();
        assert_eq!(report.kind, ErrorKind::Other);
        assert_eq!(report.status, 0);
        assert!(report.partial.is_none());
    }

    /// Every kind's wire name round-trips (and is snake_case).
    #[test]
    fn every_kind_round_trips() {
        let kinds = [
            ErrorKind::InvalidArgument,
            ErrorKind::NotImplemented,
            ErrorKind::ModelFileNotFound,
            ErrorKind::ModelLoad,
            ErrorKind::OutOfMemory,
            ErrorKind::Backend,
            ErrorKind::Unsupported,
            ErrorKind::BadStructSize,
            ErrorKind::InputTooLong,
            ErrorKind::Aborted,
            ErrorKind::OutputTruncated,
            ErrorKind::OutputRepetition,
            ErrorKind::UnsupportedRole,
            ErrorKind::VersionMismatch,
            ErrorKind::Nul,
            ErrorKind::Busy,
            ErrorKind::InputTooShort,
            ErrorKind::Other,
        ];
        for kind in kinds {
            let s = serde_json::to_string(&kind).unwrap();
            assert!(
                s.trim_matches('"')
                    .chars()
                    .all(|c| c.is_ascii_lowercase() || c == '_'),
                "{kind:?} -> {s}"
            );
            assert_eq!(serde_json::from_str::<ErrorKind>(&s).unwrap(), kind);
        }
    }
}