trevors_utilities/tests/test_compression.rs

use std::io::{Read, Write};
use tempfile::NamedTempFile;
use trevors_utilities::test_compression::TestCompression;

#[test]
fn smoke() {
    assert!(true)
}

#[test]
fn compression_round_trip() {
    let to_compress = "The quick brown fox jumps over the lazy dog.";

    let decompressed_text =
        TestCompression::decompress_to_string(&TestCompression::compress_string(to_compress));
    assert_eq!(to_compress, decompressed_text);
}

#[test]
fn file_compression_round_trip() {
    // compress string to file...
    let string_to_compress = "The quick brown fox jumps over the lazy dog.";
    let compressed_string = TestCompression::compress_string(string_to_compress);
    let mut temp_target = NamedTempFile::new().unwrap();
    let temp_reader = temp_target.reopen();

    // ...write the compressed version to a file...
    temp_target
        .write_all(&compressed_string)
        .expect("Unable to write compressed file for test");
    //
    // ...decompress from file...
    let mut compressed_read = Vec::new();
    temp_reader
        .unwrap()
        .read_to_end(&mut compressed_read)
        .expect("Unable to read compressed data for test");
    let decompresed = TestCompression::decompress_to_string(&compressed_read);
    //
    // ...verify its the same.
    assert_eq!(string_to_compress, decompresed);
}

#[test]
fn file_compression_reader() {
    // Get the 'sample text'
    let to_compress = "The quick brown fox jumps over the lazy dog.";

    // ...write it to the temp file...
    let mut temp_file = NamedTempFile::new().expect("Unable to get temp file for test");
    temp_file
        .write_all(&*TestCompression::compress_string(to_compress))
        .expect("Unable to write compressed data to temp file for test");
    let temp2_path = temp_file.path();
    let uncompressed_text = TestCompression::load_compressed_file_to_string(temp2_path);

    assert_eq!(uncompressed_text, to_compress);
}

#[test]
fn file_compression_writer() {
    let to_compress = "The quick brown fox jumps over the lazy dog.";

    let mut temp_file = NamedTempFile::new().expect("Unable to get temp file for test.");
    TestCompression::save_string_as_compressed_data(to_compress, temp_file.path());

    // read back the compressed text
    let mut read_buffer = Vec::new();
    temp_file
        .read_to_end(&mut read_buffer)
        .expect("Unable to read compressed data back.");
    let decompressed_text = TestCompression::decompress_to_string(&read_buffer);
    assert_eq!(decompressed_text, to_compress);
}

#[test]
fn compress_file() {
    // create our test file.
    let test_text = "The quick brown fox jumps over the lazy dog.";
    let mut original_file = NamedTempFile::new().unwrap();
    let compressed_file = NamedTempFile::new().unwrap();
    original_file
        .write(test_text.as_bytes())
        .expect("Unable to write original file");

    // run the method being tested
    TestCompression::compress_file(original_file.path(), compressed_file.path())
        .expect("Unable to compress temp file.");

    // verify the data in the new file matches what we expect
    let mut reader_file = compressed_file.reopen().unwrap();

    let mut result_text = Vec::new();
    reader_file
        .read_to_end(&mut result_text)
        .expect("Unable to read compressed data back to verify");
    let decompressed_text = TestCompression::decompress_to_string(&result_text);

    assert_eq!(decompressed_text, test_text);
}

#[test]
fn compress_string_to_file() {
    let to_compress = "The quick brown fox jumped over the lazy dog.";
    let compressed_text = TestCompression::compress_string(to_compress);
    let target_file = NamedTempFile::new().unwrap();
    let mut duplicate = target_file.reopen().unwrap();
    TestCompression::compress_string_to_file(to_compress, target_file.path());

    let mut file_contents = Vec::new();
    duplicate
        .read_to_end(&mut file_contents)
        .expect("Unable to read compressed file.");
    assert_eq!(file_contents, compressed_text);
}

#[test]
fn decompress_file_to_string() {
    let to_compress = "The quick brown fox jumps over the lazy dog.";
    let temp = NamedTempFile::new().unwrap();
    TestCompression::compress_string_to_file(to_compress, temp.path());
    let result = TestCompression::decompress_file_to_string(temp.path());
    assert_eq!(to_compress, result);
}

#[test]
fn compress_file_to_array() {
    let to_compress = "The quick brown fox jumps over the lazy dog.";
    let mut temp_file = NamedTempFile::new().expect("Unable to get temp file for test");
    temp_file.write_all(to_compress.as_bytes()).unwrap();

    let result = TestCompression::compress_file_to_array(temp_file.path());

    let decompressed_result = TestCompression::decompress_to_string(&result);
    assert_eq!(to_compress, decompressed_result);
}

#[test]
fn decompress_to_array() {
    let original_text = "The quick brown fox jumps over the lazy dog.";
    let compressed_data = TestCompression::compress_string(original_text);

    // Write the compressed data to a temp file
    let mut temp_file = NamedTempFile::new().expect("Failed to create temp file");
    temp_file
        .write_all(&compressed_data)
        .expect("Failed to write compressed data to file");

    // Run the method under test
    let decompressed_data = TestCompression::decompress_file_to_array(temp_file.path());

    // Convert to string to compare
    let decompressed_text = String::from_utf8(decompressed_data)
        .expect("Decompressed bytes were not valid UTF-8");
    assert_eq!(decompressed_text, original_text);

}

#[test]
#[should_panic(expected = "No such file or directory")]
fn decompress_file_panics_on_missing_path() {
    let bad_path = std::path::Path::new("/definitely/invalid/path");
    TestCompression::decompress_file_to_array(bad_path);
}