qubit-codec-misc 0.7.3

// =============================================================================
//    Copyright (c) 2026 Haixing Hu.
//
//    SPDX-License-Identifier: Apache-2.0
//
//    Licensed under the Apache License, Version 2.0.
// =============================================================================
//! Tests for Base64 encoding variants.

use qubit_codec::ValueDecoder;
use qubit_codec::ValueEncoder;
use qubit_codec_misc::Base64Codec;
use qubit_codec_misc::Base64ErrorKind;
use qubit_codec_misc::MiscCodecError;

#[test]
fn test_standard_base64_roundtrip_with_padding() {
    let codec = Base64Codec::standard();
    let encoded = codec.encode(b"hello world");

    assert_eq!("aGVsbG8gd29ybGQ=", encoded);
    assert_eq!(
        b"hello world".to_vec(),
        codec.decode(&encoded).expect("base64 should decode")
    );
}

#[test]
fn test_url_safe_base64_roundtrip_without_padding() {
    let codec = Base64Codec::url_safe_no_pad();
    let bytes = [0xfb, 0xff, 0xee, 0x00];
    let encoded = codec.encode(&bytes);

    assert_eq!("-__uAA", encoded);
    assert_eq!(
        bytes.to_vec(),
        codec.decode(&encoded).expect("url-safe base64 should decode")
    );
}

#[test]
fn test_base64_constructors_cover_padding_and_alphabet_variants() {
    assert_eq!("aGk", Base64Codec::standard_no_pad().encode(b"hi"));
    assert_eq!("++8=", Base64Codec::standard().encode(&[0xfb, 0xef]));
    assert_eq!("--8=", Base64Codec::url_safe().encode(&[0xfb, 0xef]));
    assert_eq!(
        b"hi".to_vec(),
        Base64Codec::standard_no_pad()
            .decode("aGk")
            .expect("standard no-pad base64 should decode")
    );
    assert_eq!(
        vec![0xfb, 0xef],
        Base64Codec::url_safe()
            .decode("--8=")
            .expect("url-safe padded base64 should decode")
    );
    assert_eq!(
        b"hi".to_vec(),
        Base64Codec::default()
            .decode("aGk=")
            .expect("default base64 should decode")
    );
}

#[test]
fn test_base64_codec_equality_distinguishes_engine_variants() {
    assert_eq!(Base64Codec::standard(), Base64Codec::default());
    assert_eq!(Base64Codec::url_safe_no_pad(), Base64Codec::url_safe_no_pad());
    assert_ne!(Base64Codec::standard(), Base64Codec::standard_no_pad());
    assert_ne!(Base64Codec::standard(), Base64Codec::url_safe());
}

#[test]
fn test_decode_rejects_invalid_base64() {
    let error = Base64Codec::standard()
        .decode("@")
        .expect_err("invalid base64 should fail");

    assert!(matches!(
        error,
        MiscCodecError::InvalidBase64 {
            kind: Base64ErrorKind::InvalidByte,
            input_index: Some(0),
            symbol: Some(b'@'),
            input_length: None,
            ..
        }
    ));
    let source = std::error::Error::source(&error).expect("Base64 error should retain its dependency source");
    assert_eq!(
        Some(&base64::DecodeError::InvalidByte(0, b'@')),
        source.downcast_ref::<base64::DecodeError>()
    );
}

#[test]
fn test_decode_reports_base64_error_category_and_index() {
    let invalid_last_symbol = Base64Codec::standard()
        .decode("YR==")
        .expect_err("non-canonical Base64 should fail");
    assert!(matches!(
        invalid_last_symbol,
        MiscCodecError::InvalidBase64 {
            kind: Base64ErrorKind::InvalidLastSymbol,
            input_index: Some(1),
            symbol: Some(b'R'),
            input_length: None,
            ..
        }
    ));

    let invalid_length = Base64Codec::standard()
        .decode("Y")
        .expect_err("short Base64 should fail");
    assert!(matches!(
        invalid_length,
        MiscCodecError::InvalidBase64 {
            kind: Base64ErrorKind::InvalidLength,
            input_index: None,
            symbol: None,
            input_length: Some(1),
            ..
        }
    ));
}

#[test]
fn test_base64_codec_can_be_used_through_traits() {
    let mut codec = Base64Codec::standard();
    let encoded = ValueEncoder::<[u8]>::encode(&mut codec, b"abc").expect("base64 encode should succeed");
    let decoded = ValueDecoder::<str>::decode(&mut codec, &encoded).expect("base64 decode should succeed");

    assert_eq!("YWJj", encoded);
    assert_eq!(b"abc".to_vec(), decoded);
}