tauri_utils/config/
parse.rs

1// Copyright 2019-2024 Tauri Programme within The Commons Conservancy
2// SPDX-License-Identifier: Apache-2.0
3// SPDX-License-Identifier: MIT
4
5use crate::config::Config;
6use crate::platform::Target;
7use json_patch::merge;
8use serde::de::DeserializeOwned;
9use serde_json::Value;
10use std::ffi::OsStr;
11use std::path::{Path, PathBuf};
12use thiserror::Error;
13
14/// All extensions that are possibly supported, but perhaps not enabled.
15pub const EXTENSIONS_SUPPORTED: &[&str] = &["json", "json5", "toml"];
16
17/// All configuration formats that are possibly supported, but perhaps not enabled.
18pub const SUPPORTED_FORMATS: &[ConfigFormat] =
19  &[ConfigFormat::Json, ConfigFormat::Json5, ConfigFormat::Toml];
20
21/// All configuration formats that are currently enabled.
22pub const ENABLED_FORMATS: &[ConfigFormat] = &[
23  ConfigFormat::Json,
24  #[cfg(feature = "config-json5")]
25  ConfigFormat::Json5,
26  #[cfg(feature = "config-toml")]
27  ConfigFormat::Toml,
28];
29
30/// The available configuration formats.
31#[derive(Debug, Copy, Clone)]
32pub enum ConfigFormat {
33  /// The default JSON (tauri.conf.json) format.
34  Json,
35  /// The JSON5 (tauri.conf.json5) format.
36  Json5,
37  /// The TOML (Tauri.toml file) format.
38  Toml,
39}
40
41impl ConfigFormat {
42  /// Maps the config format to its file name.
43  pub fn into_file_name(self) -> &'static str {
44    match self {
45      Self::Json => "tauri.conf.json",
46      Self::Json5 => "tauri.conf.json5",
47      Self::Toml => "Tauri.toml",
48    }
49  }
50
51  fn into_platform_file_name(self, target: Target) -> &'static str {
52    match self {
53      Self::Json => match target {
54        Target::MacOS => "tauri.macos.conf.json",
55        Target::Windows => "tauri.windows.conf.json",
56        Target::Linux => "tauri.linux.conf.json",
57        Target::Android => "tauri.android.conf.json",
58        Target::Ios => "tauri.ios.conf.json",
59      },
60      Self::Json5 => match target {
61        Target::MacOS => "tauri.macos.conf.json5",
62        Target::Windows => "tauri.windows.conf.json5",
63        Target::Linux => "tauri.linux.conf.json5",
64        Target::Android => "tauri.android.conf.json5",
65        Target::Ios => "tauri.ios.conf.json5",
66      },
67      Self::Toml => match target {
68        Target::MacOS => "Tauri.macos.toml",
69        Target::Windows => "Tauri.windows.toml",
70        Target::Linux => "Tauri.linux.toml",
71        Target::Android => "Tauri.android.toml",
72        Target::Ios => "Tauri.ios.toml",
73      },
74    }
75  }
76}
77
78/// Represents all the errors that can happen while reading the config.
79#[derive(Debug, Error)]
80#[non_exhaustive]
81pub enum ConfigError {
82  /// Failed to parse from JSON.
83  #[error("unable to parse JSON Tauri config file at {path} because {error}")]
84  FormatJson {
85    /// The path that failed to parse into JSON.
86    path: PathBuf,
87
88    /// The parsing [`serde_json::Error`].
89    error: serde_json::Error,
90  },
91
92  /// Failed to parse from JSON5.
93  #[cfg(feature = "config-json5")]
94  #[error("unable to parse JSON5 Tauri config file at {path} because {error}")]
95  FormatJson5 {
96    /// The path that failed to parse into JSON5.
97    path: PathBuf,
98
99    /// The parsing [`json5::Error`].
100    error: ::json5::Error,
101  },
102
103  /// Failed to parse from TOML.
104  #[cfg(feature = "config-toml")]
105  #[error("unable to parse toml Tauri config file at {path} because {error}")]
106  FormatToml {
107    /// The path that failed to parse into TOML.
108    path: PathBuf,
109
110    /// The parsing [`toml::Error`].
111    error: Box<::toml::de::Error>,
112  },
113
114  /// Unknown config file name encountered.
115  #[error("unsupported format encountered {0}")]
116  UnsupportedFormat(String),
117
118  /// Known file extension encountered, but corresponding parser is not enabled (cargo features).
119  #[error("supported (but disabled) format encountered {extension} - try enabling `{feature}` ")]
120  DisabledFormat {
121    /// The extension encountered.
122    extension: String,
123
124    /// The cargo feature to enable it.
125    feature: String,
126  },
127
128  /// A generic IO error with context of what caused it.
129  #[error("unable to read Tauri config file at {path} because {error}")]
130  Io {
131    /// The path the IO error occurred on.
132    path: PathBuf,
133
134    /// The [`std::io::Error`].
135    error: std::io::Error,
136  },
137}
138
139/// Determines if the given folder has a configuration file.
140pub fn folder_has_configuration_file(target: Target, folder: &Path) -> bool {
141  folder.join(ConfigFormat::Json.into_file_name()).exists()
142      || folder.join(ConfigFormat::Json5.into_file_name()).exists()
143      || folder.join(ConfigFormat::Toml.into_file_name()).exists()
144       // platform file names
145       || folder.join(ConfigFormat::Json.into_platform_file_name(target)).exists()
146      || folder.join(ConfigFormat::Json5.into_platform_file_name(target)).exists()
147      || folder.join(ConfigFormat::Toml.into_platform_file_name(target)).exists()
148}
149
150/// Determines if the given file path represents a Tauri configuration file.
151pub fn is_configuration_file(target: Target, path: &Path) -> bool {
152  path
153    .file_name()
154    .map(|file_name| {
155      file_name == OsStr::new(ConfigFormat::Json.into_file_name())
156        || file_name == OsStr::new(ConfigFormat::Json5.into_file_name())
157        || file_name == OsStr::new(ConfigFormat::Toml.into_file_name())
158      // platform file names
159      || file_name == OsStr::new(ConfigFormat::Json.into_platform_file_name(target))
160        || file_name == OsStr::new(ConfigFormat::Json5.into_platform_file_name(target))
161        || file_name == OsStr::new(ConfigFormat::Toml.into_platform_file_name(target))
162    })
163    .unwrap_or_default()
164}
165
166/// Reads the configuration from the given root directory.
167///
168/// It first looks for a `tauri.conf.json[5]` or `Tauri.toml` file on the given directory. The file must exist.
169/// Then it looks for a platform-specific configuration file:
170/// - `tauri.macos.conf.json[5]` or `Tauri.macos.toml` on macOS
171/// - `tauri.linux.conf.json[5]` or `Tauri.linux.toml` on Linux
172/// - `tauri.windows.conf.json[5]` or `Tauri.windows.toml` on Windows
173/// - `tauri.android.conf.json[5]` or `Tauri.android.toml` on Android
174/// - `tauri.ios.conf.json[5]` or `Tauri.ios.toml` on iOS
175///   Merging the configurations using [JSON Merge Patch (RFC 7396)].
176///
177/// Returns the raw configuration and the platform config path, if any.
178///
179/// [JSON Merge Patch (RFC 7396)]: https://datatracker.ietf.org/doc/html/rfc7396.
180pub fn read_from(
181  target: Target,
182  root_dir: PathBuf,
183) -> Result<(Value, Option<PathBuf>), ConfigError> {
184  let mut config: Value = parse_value(target, root_dir.join("tauri.conf.json"))?.0;
185  if let Some((platform_config, path)) = read_platform(target, root_dir)? {
186    merge(&mut config, &platform_config);
187    Ok((config, Some(path)))
188  } else {
189    Ok((config, None))
190  }
191}
192
193/// Reads the platform-specific configuration file from the given root directory if it exists.
194///
195/// Check [`read_from`] for more information.
196pub fn read_platform(
197  target: Target,
198  root_dir: PathBuf,
199) -> Result<Option<(Value, PathBuf)>, ConfigError> {
200  let platform_config_path = root_dir.join(ConfigFormat::Json.into_platform_file_name(target));
201  if does_supported_file_name_exist(target, &platform_config_path) {
202    let (platform_config, path): (Value, PathBuf) = parse_value(target, platform_config_path)?;
203    Ok(Some((platform_config, path)))
204  } else {
205    Ok(None)
206  }
207}
208
209/// Check if a supported config file exists at path.
210///
211/// The passed path is expected to be the path to the "default" configuration format, in this case
212/// JSON with `.json`.
213pub fn does_supported_file_name_exist(target: Target, path: impl Into<PathBuf>) -> bool {
214  let path = path.into();
215  let source_file_name = path.file_name().unwrap().to_str().unwrap();
216  let lookup_platform_config = ENABLED_FORMATS
217    .iter()
218    .any(|format| source_file_name == format.into_platform_file_name(target));
219  ENABLED_FORMATS.iter().any(|format| {
220    path
221      .with_file_name(if lookup_platform_config {
222        format.into_platform_file_name(target)
223      } else {
224        format.into_file_name()
225      })
226      .exists()
227  })
228}
229
230/// Parse the config from path, including alternative formats.
231///
232/// Hierarchy:
233/// 1. Check if `tauri.conf.json` exists
234///     a. Parse it with `serde_json`
235///     b. Parse it with `json5` if `serde_json` fails
236///     c. Return original `serde_json` error if all above steps failed
237/// 2. Check if `tauri.conf.json5` exists
238///     a. Parse it with `json5`
239///     b. Return error if all above steps failed
240/// 3. Check if `Tauri.json` exists
241///     a. Parse it with `toml`
242///     b. Return error if all above steps failed
243/// 4. Return error if all above steps failed
244pub fn parse(target: Target, path: impl Into<PathBuf>) -> Result<(Config, PathBuf), ConfigError> {
245  do_parse(target, path.into())
246}
247
248/// See [`parse`] for specifics, returns a JSON [`Value`] instead of [`Config`].
249pub fn parse_value(
250  target: Target,
251  path: impl Into<PathBuf>,
252) -> Result<(Value, PathBuf), ConfigError> {
253  do_parse(target, path.into())
254}
255
256fn do_parse<D: DeserializeOwned>(
257  target: Target,
258  path: PathBuf,
259) -> Result<(D, PathBuf), ConfigError> {
260  let file_name = path
261    .file_name()
262    .map(OsStr::to_string_lossy)
263    .unwrap_or_default();
264  let lookup_platform_config = ENABLED_FORMATS
265    .iter()
266    .any(|format| file_name == format.into_platform_file_name(target));
267
268  let json5 = path.with_file_name(if lookup_platform_config {
269    ConfigFormat::Json5.into_platform_file_name(target)
270  } else {
271    ConfigFormat::Json5.into_file_name()
272  });
273  let toml = path.with_file_name(if lookup_platform_config {
274    ConfigFormat::Toml.into_platform_file_name(target)
275  } else {
276    ConfigFormat::Toml.into_file_name()
277  });
278
279  let path_ext = path
280    .extension()
281    .map(OsStr::to_string_lossy)
282    .unwrap_or_default();
283
284  if path.exists() {
285    let raw = read_to_string(&path)?;
286
287    // to allow us to easily use the compile-time #[cfg], we always bind
288    #[allow(clippy::let_and_return)]
289    let json = do_parse_json(&raw, &path);
290
291    // we also want to support **valid** json5 in the .json extension if the feature is enabled.
292    // if the json5 is not valid the serde_json error for regular json will be returned.
293    // this could be a bit confusing, so we may want to encourage users using json5 to use the
294    // .json5 extension instead of .json
295    #[cfg(feature = "config-json5")]
296    let json = {
297      match do_parse_json5(&raw, &path) {
298        json5 @ Ok(_) => json5,
299
300        // assume any errors from json5 in a .json file is because it's not json5
301        Err(_) => json,
302      }
303    };
304
305    json.map(|j| (j, path))
306  } else if json5.exists() {
307    #[cfg(feature = "config-json5")]
308    {
309      let raw = read_to_string(&json5)?;
310      do_parse_json5(&raw, &json5).map(|config| (config, json5))
311    }
312
313    #[cfg(not(feature = "config-json5"))]
314    Err(ConfigError::DisabledFormat {
315      extension: ".json5".into(),
316      feature: "config-json5".into(),
317    })
318  } else if toml.exists() {
319    #[cfg(feature = "config-toml")]
320    {
321      let raw = read_to_string(&toml)?;
322      do_parse_toml(&raw, &toml).map(|config| (config, toml))
323    }
324
325    #[cfg(not(feature = "config-toml"))]
326    Err(ConfigError::DisabledFormat {
327      extension: ".toml".into(),
328      feature: "config-toml".into(),
329    })
330  } else if !EXTENSIONS_SUPPORTED.contains(&path_ext.as_ref()) {
331    Err(ConfigError::UnsupportedFormat(path_ext.to_string()))
332  } else {
333    Err(ConfigError::Io {
334      path,
335      error: std::io::ErrorKind::NotFound.into(),
336    })
337  }
338}
339
340/// "Low-level" helper to parse JSON into a [`Config`].
341///
342/// `raw` should be the contents of the file that is represented by `path`.
343pub fn parse_json(raw: &str, path: &Path) -> Result<Config, ConfigError> {
344  do_parse_json(raw, path)
345}
346
347/// "Low-level" helper to parse JSON into a JSON [`Value`].
348///
349/// `raw` should be the contents of the file that is represented by `path`.
350pub fn parse_json_value(raw: &str, path: &Path) -> Result<Value, ConfigError> {
351  do_parse_json(raw, path)
352}
353
354fn do_parse_json<D: DeserializeOwned>(raw: &str, path: &Path) -> Result<D, ConfigError> {
355  serde_json::from_str(raw).map_err(|error| ConfigError::FormatJson {
356    path: path.into(),
357    error,
358  })
359}
360
361/// "Low-level" helper to parse JSON5 into a [`Config`].
362///
363/// `raw` should be the contents of the file that is represented by `path`. This function requires
364/// the `config-json5` feature to be enabled.
365#[cfg(feature = "config-json5")]
366pub fn parse_json5(raw: &str, path: &Path) -> Result<Config, ConfigError> {
367  do_parse_json5(raw, path)
368}
369
370/// "Low-level" helper to parse JSON5 into a JSON [`Value`].
371///
372/// `raw` should be the contents of the file that is represented by `path`. This function requires
373/// the `config-json5` feature to be enabled.
374#[cfg(feature = "config-json5")]
375pub fn parse_json5_value(raw: &str, path: &Path) -> Result<Value, ConfigError> {
376  do_parse_json5(raw, path)
377}
378
379#[cfg(feature = "config-json5")]
380fn do_parse_json5<D: DeserializeOwned>(raw: &str, path: &Path) -> Result<D, ConfigError> {
381  ::json5::from_str(raw).map_err(|error| ConfigError::FormatJson5 {
382    path: path.into(),
383    error,
384  })
385}
386
387#[cfg(feature = "config-toml")]
388fn do_parse_toml<D: DeserializeOwned>(raw: &str, path: &Path) -> Result<D, ConfigError> {
389  ::toml::from_str(raw).map_err(|error| ConfigError::FormatToml {
390    path: path.into(),
391    error: Box::new(error),
392  })
393}
394
395/// Helper function to wrap IO errors from [`std::fs::read_to_string`] into a [`ConfigError`].
396fn read_to_string(path: &Path) -> Result<String, ConfigError> {
397  std::fs::read_to_string(path).map_err(|error| ConfigError::Io {
398    path: path.into(),
399    error,
400  })
401}
tauri_utils/config/parse.rs

tauri_utils/config/
parse.rs
