Add encode_uri_component function (#2052)

Cargo.toml

@@ -36,6 +36,7 @@ lexiclean = "0.0.1"
 libc = "0.2.0"
 log = "0.4.4"
 num_cpus = "1.15.0"
+percent-encoding = "2.3.1"
 rand = "0.8.5"
 regex = "1.10.4"
 semver = "1.0.20"

README.md

@@ -1427,6 +1427,9 @@ The process ID is: 420
 - `prepend(prefix, s)`<sup>master</sup> Prepend `prefix` to
   whitespace-separated strings in `s`. `prepend('src/', 'foo bar baz')` →
   `'src/foo src/bar src/baz'`
+- `encode_uri_component(s)`<sup>master</sup> - Percent-encode characters in `s`
+  except `[A-Za-z0-9_.!~*'()-]`, matching the behavior of the
+  [JavaScript `encodeURIComponent` function](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/encodeURIComponent).
 - `quote(s)` - Replace all single quotes with `'\''` and prepend and append
   single quotes to `s`. This is sufficient to escape special characters for
   many shells, including most Bourne shell descendants.

src/function.rs

@@ -35,6 +35,7 @@ pub(crate) fn get(name: &str) -> Option<Function> {
     "config_local_directory" => Nullary(|_| dir("local config", dirs::config_local_dir)),
     "data_directory" => Nullary(|_| dir("data", dirs::data_dir)),
     "data_local_directory" => Nullary(|_| dir("local data", dirs::data_local_dir)),
+    "encode_uri_component" => Unary(encode_uri_component),
     "env" => UnaryOpt(env),
     "env_var" => Unary(env_var),
     "env_var_or_default" => Binary(env_var_or_default),
@@ -204,6 +205,20 @@ fn dir(name: &'static str, f: fn() -> Option<PathBuf>) -> Result<String, String>
   }
 }
 
+fn encode_uri_component(_evaluator: &Evaluator, s: &str) -> Result<String, String> {
+  static PERCENT_ENCODE: percent_encoding::AsciiSet = percent_encoding::NON_ALPHANUMERIC
+    .remove(b'-')
+    .remove(b'_')
+    .remove(b'.')
+    .remove(b'!')
+    .remove(b'~')
+    .remove(b'*')
+    .remove(b'\'')
+    .remove(b'(')
+    .remove(b')');
+  Ok(percent_encoding::utf8_percent_encode(s, &PERCENT_ENCODE).to_string())
+}
+
 fn env_var(evaluator: &Evaluator, key: &str) -> Result<String, String> {
   use std::env::VarError::*;
 

tests/functions.rs

@@ -793,3 +793,12 @@ fn canonicalize() {
     .stdout_regex(".*/justfile")
     .run();
 }
+
+#[test]
+fn encode_uri_component() {
+  Test::new()
+    .justfile("x := encode_uri_component(\"0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ!\\\"#$%&'()*+,-./:;<=>?@[\\\\]^_`{|}~ \\t\\r\\n🌐\")")
+    .args(["--evaluate", "x"])
+    .stdout("0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ!%22%23%24%25%26'()*%2B%2C-.%2F%3A%3B%3C%3D%3E%3F%40%5B%5C%5D%5E_%60%7B%7C%7D~%20%09%0D%0A%F0%9F%8C%90")
+    .run();
+}