cargo-dry4rust 0.3.0

A cargo subcommand that detects duplicate and near-duplicate code blocks in Rust codebases using AST normalization
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140

// Copyright (c) 2026 Matjaz Domen Pecan
// Copyright 2026 Umberto Gotti <umberto.gotti@umbertogotti.dev>
// Licensed under the MIT License
// SPDX-License-Identifier: MIT

use clap::CommandFactory;
use clap::Parser;
use dry4rust::cli::command::Command;

/// The smallest thing that can parse a `Command`, so these tests are about the
/// subcommand definitions and not about `main`'s surrounding flags.
#[derive(Parser)]
struct Harness {
    #[command(subcommand)]
    command: Command,
}

fn parsed(args: &[&str]) -> Command {
    Harness::try_parse_from(args)
        .expect("the arguments parse")
        .command
}

#[test]
fn augment_subcommands_declares_every_command_the_tool_serves() {
    // Arrange
    let command = Harness::command();

    // Act
    let names: Vec<&str> = command
        .get_subcommands()
        .map(clap::Command::get_name)
        .collect();

    // Assert
    assert_eq!(
        names,
        vec![
            "stats", "report", "check", "ignore", "ignored", "cleanup", "baseline"
        ],
        "the dispatcher matches on all seven; a new one added here and nowhere \
         else would be unreachable"
    );
}

#[test]
fn augment_subcommands_rejects_a_subcommand_that_does_not_exist() {
    // Arrange & Act
    let outcome = Harness::try_parse_from(["dry4rust", "polish"]);

    // Assert
    assert!(
        outcome.is_err(),
        "a name close to nothing is a typo, not a default"
    );
}

#[test]
fn from_arg_matches_leaves_every_ceiling_unset_when_check_is_given_none() {
    // Arrange & Act
    let command = parsed(&["dry4rust", "check"]);

    // Assert
    assert!(matches!(
        command,
        Command::Check {
            max_exact: None,
            max_near: None,
            max_exact_percent: None,
            max_near_percent: None,
        }
    ));
}

#[test]
fn from_arg_matches_reads_baseline_with_its_dry_run_flag() {
    // Arrange & Act
    let command = parsed(&["dry4rust", "baseline", "--dry-run"]);

    // Assert
    assert!(matches!(command, Command::Baseline { dry_run: true }));
}

#[test]
fn from_arg_matches_reads_check_with_all_four_ceilings() {
    // Arrange & Act
    let command = parsed(&[
        "dry4rust",
        "check",
        "--max-exact",
        "0",
        "--max-near",
        "3",
        "--max-exact-percent",
        "5",
        "--max-near-percent",
        "10.5",
    ]);

    // Assert
    let Command::Check {
        max_exact,
        max_near,
        max_exact_percent,
        max_near_percent,
    } = command
    else {
        panic!("check parses to Check");
    };
    assert_eq!(max_exact, Some(0));
    assert_eq!(max_near, Some(3));
    assert_eq!(max_exact_percent, Some(5.0));
    assert_eq!(max_near_percent, Some(10.5));
}

#[test]
fn from_arg_matches_reads_ignore_with_its_fingerprint_and_reason() {
    // Arrange & Act
    let command = parsed(&[
        "dry4rust",
        "ignore",
        "deadbeef12345678",
        "--reason",
        "trait impls are meant to look alike",
    ]);

    // Assert
    let Command::Ignore {
        fingerprint,
        reason,
    } = command
    else {
        panic!("ignore parses to Ignore");
    };
    assert_eq!(fingerprint, "deadbeef12345678");
    assert_eq!(
        reason.as_deref(),
        Some("trait impls are meant to look alike")
    );
}