1#![deny(warnings)]
2
3use std::path::PathBuf;
4
5use clap::Parser;
6
7mod create_parent_directory;
8mod create_thumbnail;
9mod errors;
10mod get_thumbnail_dimensions;
11mod is_animated_gif;
12
13use crate::create_thumbnail::create_thumbnail;
14use crate::get_thumbnail_dimensions::TargetDimension;
15
16#[derive(Debug, Parser)]
17#[clap(version, about)]
18struct Cli {
19    /// Path to the image to be thumbnailed
20    path: PathBuf,
21
22    /// Path to the directory to save the thumbnail in
23    #[arg(long)]
24    out_dir: PathBuf,
25
26    /// Height of the thumbnail to create
27    #[arg(long)]
28    height: Option<u32>,
29
30    /// Width of the thumbnail to create
31    #[arg(long)]
32    width: Option<u32>,
33}
34
35fn main() {
36    let cli = Cli::parse();
37
38    let target = match (cli.width, cli.height) {
39        (Some(w), Some(h)) => TargetDimension::BoundingBox(w, h),
40        (Some(w), None) => TargetDimension::MaxWidth(w),
41        (None, Some(h)) => TargetDimension::MaxHeight(h),
42        _ => {
43            eprintln!(
44                "Failed to create thumbnail: you must pass at least one of --width or --height"
45            );
46            std::process::exit(1);
47        }
48    };
49
50    match create_thumbnail(&cli.path, &cli.out_dir, target) {
51        Ok(thumbnail_path) => print!("{}", thumbnail_path.display()),
52        Err(e) => {
53            eprintln!("{}", e);
54            std::process::exit(1);
55        }
56    };
57}
58
59#[expect(
60    deprecated,
61    reason = "cargo_bin is deprecated, cargo_bin! is not, `use` does not differentiate them. See https://github.com/assert-rs/assert_cmd/issues/258"
62)]
63#[cfg(test)]
64mod test_cli {
65    use std::path::PathBuf;
66
67    use assert_cmd::Command;
68    use predicates::prelude::*;
69
70    use crate::test_utils::get_dimensions;
71
72    #[test]
73    fn it_creates_a_thumbnail_with_max_width() {
74        Command::cargo_bin("create_thumbnail")
75            .unwrap()
76            .args(&["src/tests/red.png", "--width=50", "--out-dir=/tmp"])
77            .assert()
78            .success()
79            .stdout("/tmp/red.png")
80            .stderr("");
81
82        assert_eq!(get_dimensions(&PathBuf::from("/tmp/red.png")), (50, 100));
83    }
84
85    #[test]
86    fn it_creates_a_thumbnail_with_max_height() {
87        Command::cargo_bin("create_thumbnail")
88            .unwrap()
89            .args(&["src/tests/noise.jpg", "--height=128", "--out-dir=/tmp"])
90            .assert()
91            .success()
92            .stdout("/tmp/noise.jpg")
93            .stderr("");
94
95        assert_eq!(get_dimensions(&PathBuf::from("/tmp/noise.jpg")), (64, 128));
96    }
97
98    #[test]
99    fn it_creates_a_thumbnail_with_a_bounding_box() {
100        Command::cargo_bin("create_thumbnail")
101            .unwrap()
102            .args(&[
103                "src/tests/noise.jpg",
104                "--width=64",
105                "--height=64",
106                "--out-dir=/tmp",
107            ])
108            .assert()
109            .success()
110            .stdout("/tmp/noise.jpg")
111            .stderr("");
112
113        assert_eq!(get_dimensions(&PathBuf::from("/tmp/noise.jpg")), (32, 64));
114    }
115
116    #[test]
117    fn it_fails_if_you_pass_neither_width_nor_height() {
118        Command::cargo_bin("create_thumbnail")
119            .unwrap()
120            .args(&["src/tests/red.png", "--out-dir=/tmp"])
121            .assert()
122            .failure()
123            .code(1)
124            .stdout("")
125            .stderr(
126                "Failed to create thumbnail: you must pass at least one of --width or --height\n",
127            );
128    }
129
130    #[test]
131    fn it_fails_if_you_pass_a_non_existent_file() {
132        Command::cargo_bin("create_thumbnail")
133            .unwrap()
134            .args(&["doesnotexist.txt", "--width=50", "--out-dir=/tmp"])
135            .assert()
136            .failure()
137            .code(1)
138            .stdout("")
139            .stderr("Failed to open image: No such file or directory (os error 2)\n");
140    }
141
142    #[test]
143    fn it_fails_if_you_pass_a_non_image() {
144        Command::cargo_bin("create_thumbnail")
145            .unwrap()
146            .args(&["Cargo.toml", "--width=50", "--out-dir=/tmp"])
147            .assert()
148            .failure()
149            .code(1)
150            .stdout("")
151            .stderr("Failed to open image: The file extension `.\"toml\"` was not recognized as an image format\n");
152    }
153
154    // TODO: Improve this error message.
155    //
156    // It's good to know the tool won't completely break when this happens, but ideally
157    // we'd return a more meaningful error message in this case.
158    #[test]
159    fn it_fails_if_out_dir_is_a_file() {
160        Command::cargo_bin("create_thumbnail")
161            .unwrap()
162            .args(&["src/images/noise.jpg", "--width=50", "--out-dir=README.md"])
163            .assert()
164            .failure()
165            .code(1)
166            .stdout("")
167            .stderr("I/O error: File exists (os error 17)\n");
168    }
169
170    #[test]
171    fn it_fails_if_you_try_to_overwrite_the_original_file() {
172        Command::cargo_bin("create_thumbnail")
173            .unwrap()
174            .args(&["src/images/noise.jpg", "--width=50", "--out-dir=src/images"])
175            .assert()
176            .failure()
177            .code(1)
178            .stdout("")
179            .stderr("Cannot write thumbnail to the same path as the original image\n");
180    }
181
182    #[test]
183    fn it_prints_the_version() {
184        // Match strings like `create_thumbnail 1.2.3`
185        let is_version_string =
186            predicate::str::is_match(r"^create_thumbnail [0-9]+\.[0-9]+\.[0-9]+\n$").unwrap();
187
188        Command::cargo_bin("create_thumbnail")
189            .unwrap()
190            .arg("--version")
191            .assert()
192            .success()
193            .stdout(is_version_string)
194            .stderr("");
195    }
196
197    #[test]
198    fn it_prints_the_help() {
199        // Match strings like `create_thumbnail 1.2.3`
200        let is_help_text =
201            predicate::str::is_match(r"create_thumbnail \[OPTIONS\] --out-dir").unwrap();
202
203        Command::cargo_bin("create_thumbnail")
204            .unwrap()
205            .arg("--help")
206            .assert()
207            .success()
208            .stdout(is_help_text)
209            .stderr("");
210    }
211}
212
213#[cfg(test)]
214pub mod test_utils {
215    use std::path::PathBuf;
216
217    use image::GenericImageView;
218
219    /// Return a path to a temporary directory to use for testing.
220    ///
221    /// This function does *not* create the directory, just the path.
222    pub fn test_dir() -> PathBuf {
223        let tmp_dir = tempfile::tempdir().unwrap();
224
225        tmp_dir.path().to_owned()
226    }
227
228    /// Return the dimensions for an image.
229    pub fn get_dimensions(path: &PathBuf) -> (u32, u32) {
230        let img = image::open(path).unwrap();
231
232        img.dimensions()
233    }
234}