src/tools/rustfmt/src/test/configuration_snippet.rs

   1 use std::collections::{HashMap, HashSet};
   2 use std::fs;
   3 use std::io::{BufRead, BufReader, Write};
   4 use std::iter::Enumerate;
   5 use std::path::{Path, PathBuf};
   6
   7 use super::{print_mismatches, write_message, DIFF_CONTEXT_SIZE};
   8 use crate::config::{Config, EmitMode, Verbosity};
   9 use crate::rustfmt_diff::{make_diff, Mismatch};
  10 use crate::{Input, Session};
  11
  12 const CONFIGURATIONS_FILE_NAME: &str = "Configurations.md";
  13
  14 // This enum is used to represent one of three text features in Configurations.md: a block of code
  15 // with its starting line number, the name of a rustfmt configuration option, or the value of a
  16 // rustfmt configuration option.
  17 enum ConfigurationSection {
  18     CodeBlock((String, u32)), // (String: block of code, u32: line number of code block start)
  19     ConfigName(String),
  20     ConfigValue(String),
  21 }
  22
  23 impl ConfigurationSection {
  24     fn get_section<I: Iterator<Item = String>>(
  25         file: &mut Enumerate<I>,
  26     ) -> Option<ConfigurationSection> {
  27         lazy_static! {
  28             static ref CONFIG_NAME_REGEX: regex::Regex =
  29                 regex::Regex::new(r"^## `([^`]+)`").expect("failed creating configuration pattern");
  30             static ref CONFIG_VALUE_REGEX: regex::Regex =
  31                 regex::Regex::new(r#"^#### `"?([^`"]+)"?`"#)
  32                     .expect("failed creating configuration value pattern");
  33         }
  34
  35         loop {
  36             match file.next() {
  37                 Some((i, line)) => {
  38                     if line.starts_with("```rust") {
  39                         // Get the lines of the code block.
  40                         let lines: Vec<String> = file
  41                             .map(|(_i, l)| l)
  42                             .take_while(|l| !l.starts_with("```"))
  43                             .collect();
  44                         let block = format!("{}\n", lines.join("\n"));
  45
  46                         // +1 to translate to one-based indexing
  47                         // +1 to get to first line of code (line after "```")
  48                         let start_line = (i + 2) as u32;
  49
  50                         return Some(ConfigurationSection::CodeBlock((block, start_line)));
  51                     } else if let Some(c) = CONFIG_NAME_REGEX.captures(&line) {
  52                         return Some(ConfigurationSection::ConfigName(String::from(&c[1])));
  53                     } else if let Some(c) = CONFIG_VALUE_REGEX.captures(&line) {
  54                         return Some(ConfigurationSection::ConfigValue(String::from(&c[1])));
  55                     }
  56                 }
  57                 None => return None, // reached the end of the file
  58             }
  59         }
  60     }
  61 }
  62
  63 // This struct stores the information about code blocks in the configurations
  64 // file, formats the code blocks, and prints formatting errors.
  65 struct ConfigCodeBlock {
  66     config_name: Option<String>,
  67     config_value: Option<String>,
  68     code_block: Option<String>,
  69     code_block_start: Option<u32>,
  70 }
  71
  72 impl ConfigCodeBlock {
  73     fn new() -> ConfigCodeBlock {
  74         ConfigCodeBlock {
  75             config_name: None,
  76             config_value: None,
  77             code_block: None,
  78             code_block_start: None,
  79         }
  80     }
  81
  82     fn set_config_name(&mut self, name: Option<String>) {
  83         self.config_name = name;
  84         self.config_value = None;
  85     }
  86
  87     fn set_config_value(&mut self, value: Option<String>) {
  88         self.config_value = value;
  89     }
  90
  91     fn set_code_block(&mut self, code_block: String, code_block_start: u32) {
  92         self.code_block = Some(code_block);
  93         self.code_block_start = Some(code_block_start);
  94     }
  95
  96     fn get_block_config(&self) -> Config {
  97         let mut config = Config::default();
  98         config.set().verbose(Verbosity::Quiet);
  99         if self.config_name.is_some() && self.config_value.is_some() {
 100             config.override_value(
 101                 self.config_name.as_ref().unwrap(),
 102                 self.config_value.as_ref().unwrap(),
 103             );
 104         }
 105         config
 106     }
 107
 108     fn code_block_valid(&self) -> bool {
 109         // We never expect to not have a code block.
 110         assert!(self.code_block.is_some() && self.code_block_start.is_some());
 111
 112         // See if code block begins with #![rustfmt::skip].
 113         let fmt_skip = self
 114             .code_block
 115             .as_ref()
 116             .unwrap()
 117             .lines()
 118             .nth(0)
 119             .unwrap_or("")
 120             == "#![rustfmt::skip]";
 121
 122         if self.config_name.is_none() && !fmt_skip {
 123             write_message(&format!(
 124                 "No configuration name for {}:{}",
 125                 CONFIGURATIONS_FILE_NAME,
 126                 self.code_block_start.unwrap()
 127             ));
 128             return false;
 129         }
 130         if self.config_value.is_none() && !fmt_skip {
 131             write_message(&format!(
 132                 "No configuration value for {}:{}",
 133                 CONFIGURATIONS_FILE_NAME,
 134                 self.code_block_start.unwrap()
 135             ));
 136             return false;
 137         }
 138         true
 139     }
 140
 141     fn has_parsing_errors<T: Write>(&self, session: &Session<'_, T>) -> bool {
 142         if session.has_parsing_errors() {
 143             write_message(&format!(
 144                 "\u{261d}\u{1f3fd} Cannot format {}:{}",
 145                 CONFIGURATIONS_FILE_NAME,
 146                 self.code_block_start.unwrap()
 147             ));
 148             return true;
 149         }
 150
 151         false
 152     }
 153
 154     fn print_diff(&self, compare: Vec<Mismatch>) {
 155         let mut mismatches = HashMap::new();
 156         mismatches.insert(PathBuf::from(CONFIGURATIONS_FILE_NAME), compare);
 157         print_mismatches(mismatches, |line_num| {
 158             format!(
 159                 "\nMismatch at {}:{}:",
 160                 CONFIGURATIONS_FILE_NAME,
 161                 line_num + self.code_block_start.unwrap() - 1
 162             )
 163         });
 164     }
 165
 166     fn formatted_has_diff(&self, text: &str) -> bool {
 167         let compare = make_diff(self.code_block.as_ref().unwrap(), text, DIFF_CONTEXT_SIZE);
 168         if !compare.is_empty() {
 169             self.print_diff(compare);
 170             return true;
 171         }
 172
 173         false
 174     }
 175
 176     // Return a bool indicating if formatting this code block is an idempotent
 177     // operation. This function also triggers printing any formatting failure
 178     // messages.
 179     fn formatted_is_idempotent(&self) -> bool {
 180         // Verify that we have all of the expected information.
 181         if !self.code_block_valid() {
 182             return false;
 183         }
 184
 185         let input = Input::Text(self.code_block.as_ref().unwrap().to_owned());
 186         let mut config = self.get_block_config();
 187         config.set().emit_mode(EmitMode::Stdout);
 188         let mut buf: Vec<u8> = vec![];
 189
 190         {
 191             let mut session = Session::new(config, Some(&mut buf));
 192             session.format(input).unwrap();
 193             if self.has_parsing_errors(&session) {
 194                 return false;
 195             }
 196         }
 197
 198         !self.formatted_has_diff(&String::from_utf8(buf).unwrap())
 199     }
 200
 201     // Extract a code block from the iterator. Behavior:
 202     // - Rust code blocks are identifed by lines beginning with "```rust".
 203     // - One explicit configuration setting is supported per code block.
 204     // - Rust code blocks with no configuration setting are illegal and cause an
 205     //   assertion failure, unless the snippet begins with #![rustfmt::skip].
 206     // - Configuration names in Configurations.md must be in the form of
 207     //   "## `NAME`".
 208     // - Configuration values in Configurations.md must be in the form of
 209     //   "#### `VALUE`".
 210     fn extract<I: Iterator<Item = String>>(
 211         file: &mut Enumerate<I>,
 212         prev: Option<&ConfigCodeBlock>,
 213         hash_set: &mut HashSet<String>,
 214     ) -> Option<ConfigCodeBlock> {
 215         let mut code_block = ConfigCodeBlock::new();
 216         code_block.config_name = prev.and_then(|cb| cb.config_name.clone());
 217
 218         loop {
 219             match ConfigurationSection::get_section(file) {
 220                 Some(ConfigurationSection::CodeBlock((block, start_line))) => {
 221                     code_block.set_code_block(block, start_line);
 222                     break;
 223                 }
 224                 Some(ConfigurationSection::ConfigName(name)) => {
 225                     assert!(
 226                         Config::is_valid_name(&name),
 227                         "an unknown configuration option was found: {}",
 228                         name
 229                     );
 230                     assert!(
 231                         hash_set.remove(&name),
 232                         "multiple configuration guides found for option {}",
 233                         name
 234                     );
 235                     code_block.set_config_name(Some(name));
 236                 }
 237                 Some(ConfigurationSection::ConfigValue(value)) => {
 238                     code_block.set_config_value(Some(value));
 239                 }
 240                 None => return None, // end of file was reached
 241             }
 242         }
 243
 244         Some(code_block)
 245     }
 246 }
 247
 248 #[test]
 249 fn configuration_snippet_tests() {
 250     super::init_log();
 251     let blocks = get_code_blocks();
 252     let failures = blocks
 253         .iter()
 254         .map(ConfigCodeBlock::formatted_is_idempotent)
 255         .fold(0, |acc, r| acc + (!r as u32));
 256
 257     // Display results.
 258     println!("Ran {} configurations tests.", blocks.len());
 259     assert_eq!(failures, 0, "{} configurations tests failed", failures);
 260 }
 261
 262 // Read Configurations.md and build a `Vec` of `ConfigCodeBlock` structs with one
 263 // entry for each Rust code block found.
 264 fn get_code_blocks() -> Vec<ConfigCodeBlock> {
 265     let mut file_iter = BufReader::new(
 266         fs::File::open(Path::new(CONFIGURATIONS_FILE_NAME))
 267             .unwrap_or_else(|_| panic!("couldn't read file {}", CONFIGURATIONS_FILE_NAME)),
 268     )
 269     .lines()
 270     .map(Result::unwrap)
 271     .enumerate();
 272     let mut code_blocks: Vec<ConfigCodeBlock> = Vec::new();
 273     let mut hash_set = Config::hash_set();
 274
 275     while let Some(cb) = ConfigCodeBlock::extract(&mut file_iter, code_blocks.last(), &mut hash_set)
 276     {
 277         code_blocks.push(cb);
 278     }
 279
 280     for name in hash_set {
 281         if !Config::is_hidden_option(&name) {
 282             panic!("{} does not have a configuration guide", name);
 283         }
 284     }
 285
 286     code_blocks
 287 }