| 5 | 5 | | pub struct Options { |
| 6 | 6 | | /// The name to greet, if one was given. |
| 7 | 7 | | pub name: Option<String>, |
| 8 | + | /// Whether to upper-case the greeting (`--shout`). |
| 9 | + | pub shout: bool, |
| 8 | 10 | | } |
| 9 | 11 | | |
| 10 | 12 | | /// Parses command-line arguments (excluding the program name). |
| 11 | 13 | | /// |
| 12 | | − | /// Arguments starting with `--` are treated as flags and skipped; the name is |
| 13 | | − | /// the first remaining argument. |
| 14 | + | /// `--shout` sets [`Options::shout`]; other arguments starting with `--` are |
| 15 | + | /// treated as flags and skipped. The name is the first remaining argument. |
| 14 | 16 | | pub fn parse_args<I: IntoIterator<Item = String>>(args: I) -> Options { |
| 15 | | − | let name = args.into_iter().find(|arg| !arg.starts_with("--")); |
| 16 | | − | Options { name } |
| 17 | + | let mut options = Options::default(); |
| 18 | + | for arg in args { |
| 19 | + | if arg == "--shout" { |
| 20 | + | options.shout = true; |
| 21 | + | } else if !arg.starts_with("--") && options.name.is_none() { |
| 22 | + | options.name = Some(arg); |
| 23 | + | } |
| 24 | + | } |
| 25 | + | options |
| 17 | 26 | | } |
| 18 | 27 | | |
| 28 | + | /// `text` upper-cased. |
| 29 | + | pub fn shout(text: &str) -> String { |
| 30 | + | text.to_uppercase() |
| 31 | + | } |
| 32 | + | |
| 19 | 33 | | /// The greeting for `name`. |
| 20 | 34 | | pub fn greeting(name: &str) -> String { |
| 21 | 35 | | let trimmed = name.trim(); |
| ⋯ |
| 57 | 71 | | } |
| 58 | 72 | | |
| 59 | 73 | | #[test] |
| 74 | + | fn parse_args_shout_defaults_off() { |
| 75 | + | assert!(!parse_args(args(&["Ada"])).shout); |
| 76 | + | } |
| 77 | + | |
| 78 | + | #[test] |
| 79 | + | fn parse_args_shout_before_name() { |
| 80 | + | let options = parse_args(args(&["--shout", "Ada"])); |
| 81 | + | assert!(options.shout); |
| 82 | + | assert_eq!(options.name.as_deref(), Some("Ada")); |
| 83 | + | } |
| 84 | + | |
| 85 | + | #[test] |
| 86 | + | fn parse_args_shout_after_name() { |
| 87 | + | let options = parse_args(args(&["Ada", "--shout"])); |
| 88 | + | assert!(options.shout); |
| 89 | + | assert_eq!(options.name.as_deref(), Some("Ada")); |
| 90 | + | } |
| 91 | + | |
| 92 | + | #[test] |
| 93 | + | fn parse_args_shout_alone() { |
| 94 | + | let options = parse_args(args(&["--shout"])); |
| 95 | + | assert!(options.shout); |
| 96 | + | assert_eq!(options.name, None); |
| 97 | + | } |
| 98 | + | |
| 99 | + | #[test] |
| 100 | + | fn shout_upper_cases_greeting() { |
| 101 | + | assert_eq!(shout(&greeting("Ada")), "HELLO, ADA!"); |
| 102 | + | } |
| 103 | + | |
| 104 | + | #[test] |
| 60 | 105 | | fn greets_by_name() { |
| 61 | 106 | | assert_eq!(greeting("Ada"), "Hello, Ada!"); |
| 62 | 107 | | } |