Add validate_package_name crate

Cargo.lock

@@ -1850,18 +1850,18 @@ dependencies = [
 
 [[package]]
 name = "thiserror"
-version = "1.0.61"
+version = "1.0.62"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c546c80d6be4bc6a00c0f01730c08df82eaa7a7a61f11d656526506112cc1709"
+checksum = "f2675633b1499176c2dff06b0856a27976a8f9d436737b4cf4f312d4d91d8bbb"
 dependencies = [
  "thiserror-impl",
 ]
 
 [[package]]
 name = "thiserror-impl"
-version = "1.0.61"
+version = "1.0.62"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "46c3384250002a6d5af4d114f2845d37b57521033f30d5c3f46c4d70e1197533"
+checksum = "d20468752b09f49e909e55a5d338caa8bedf615594e9d80bc4c565d30faf798c"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -2113,12 +2113,28 @@ dependencies = [
  "percent-encoding",
 ]
 
+[[package]]
+name = "urlencoding"
+version = "2.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "daf8dba3b7eb870caf1ddeed7bc9d2a049f3cfdfae7cb521b087cc33ae4c49da"
+
 [[package]]
 name = "utf8parse"
 version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "06abde3611657adf66d383f00b093d7faecc7fa57071cce2578660c9f1010821"
 
+[[package]]
+name = "validate_package_name"
+version = "0.2.0"
+dependencies = [
+ "lazy_static",
+ "regex",
+ "thiserror",
+ "urlencoding",
+]
+
 [[package]]
 name = "valuable"
 version = "0.1.0"

Cargo.toml

@@ -1,3 +1,3 @@
 [workspace]
 resolver = "2"
-members = ["crates/*"]
+members = ["crates/*"]

crates/validate_package_name/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "validate_package_name"
+version = "0.2.0"
+edition = "2021"
+
+[dependencies]
+lazy_static = "1.5.0"
+regex = "1.10.5"
+thiserror = "1.0.62"
+urlencoding = "2.1.3"

crates/validate_package_name/src/banned_names.rs

@@ -0,0 +1,59 @@
+/// All the names **not** allowed.
+#[cfg(not(tarpaulin_include))]
+const BANNED_NAMES: [&str; 47] = [
+    "node_modules",
+    "favicon.ico",
+    // https://github.com/juliangruber/builtins/blob/main/index.js (used by npm)
+    "assert",
+    "buffer",
+    "child_process",
+    "cluster",
+    "console",
+    "constants",
+    "crypto",
+    "dgram",
+    "dns",
+    "domain",
+    "events",
+    "fs",
+    "http",
+    "https",
+    "module",
+    "net",
+    "os",
+    "path",
+    "punycode",
+    "querystring",
+    "readline",
+    "repl",
+    "stream",
+    "string_decoder",
+    "sys",
+    "timers",
+    "tls",
+    "tty",
+    "url",
+    "util",
+    "vm",
+    "zlib",
+    // also from npm `builtins`, but it's the version-locked modules
+    "freelist",
+    "v8",
+    "process",
+    "inspector",
+    "async_hooks",
+    "http2",
+    "perf_hooks",
+    "trace_events",
+    "worker_threads",
+    "node:test",
+    // also from npm `builtins`, but it's the experimental modules
+    "worker_threads",
+    "wasi",
+    "diagnostics_channel",
+];
+
+#[allow(clippy::ptr_arg)]
+pub fn is_banned(name: &String) -> bool {
+    BANNED_NAMES.contains(&name.to_lowercase().as_str())
+}

crates/validate_package_name/src/lib.rs

@@ -0,0 +1,209 @@
+use lazy_static::lazy_static;
+use regex::Regex;
+use urlencoding::encode;
+
+mod banned_names;
+use banned_names::is_banned;
+
+lazy_static! {
+    static ref SCOPED_PACKAGE_REGEX: Regex = Regex::new("^(?:@([^/]+?)[/])?([^/]+?)$").unwrap();
+}
+
+const MAX_LEN: usize = 214;
+
+#[derive(thiserror::Error, Debug)]
+pub enum Error {
+    #[error("package name must not be empty")]
+    NameEmpty,
+
+    #[error("package name cannot start with a period or underscore")]
+    InvalidStartingChar,
+
+    #[error("package name cannot contain leading or trailing spaces")]
+    LeadingOrTrailingSpaces,
+
+    #[error("package name is blacklisted or is a core module name")]
+    NameNotAllowed,
+
+    #[error("package name cannot contain more than 214 characters")]
+    NameTooLong,
+
+    #[error("package name cannot contain capital letters")]
+    CapsNotAllowed,
+
+    #[error("scoped package name is invalid")]
+    ScopedPackageNameInvalid,
+
+    #[error("package name can only contain URL-friendly characters")]
+    NameMustBeUrlFriendly,
+}
+
+/// Validates an `npm` package name.
+///
+/// ```rust
+/// use validate_package_name::validate;
+///
+/// assert!(validate(&String::from("hello")).is_ok())
+/// ```
+///
+/// # Errors
+/// This function can fail if the package name is invalid.
+pub fn validate(name: &String) -> Result<(), Error> {
+    if name.is_empty() {
+        return Err(Error::NameEmpty);
+    }
+
+    if name.starts_with('.') || name.starts_with('_') {
+        return Err(Error::InvalidStartingChar);
+    }
+
+    if name.trim() != name {
+        return Err(Error::LeadingOrTrailingSpaces);
+    }
+
+    if is_banned(name) {
+        return Err(Error::NameNotAllowed);
+    }
+
+    if name.len() > MAX_LEN {
+        return Err(Error::NameTooLong);
+    }
+
+    if &name.to_lowercase() != name {
+        return Err(Error::CapsNotAllowed);
+    }
+
+    if &encode(name).into_owned() != name {
+        let name_match = SCOPED_PACKAGE_REGEX.captures(name);
+
+        if let Some(matches) = name_match {
+            // The regex returns **three** matches:
+            //
+            // - the full name ("@custard/hey")
+            // - the user ("custard"),
+            // - the package ("hi")
+
+            if matches.len() != 3 || matches.get(1).is_none() || matches.get(2).is_none() {
+                return Err(Error::ScopedPackageNameInvalid);
+            }
+
+            let user = &matches[1];
+            let pkg = &matches[2];
+
+            if encode(user) == user && encode(pkg) == pkg {
+                return Ok(());
+            }
+        }
+
+        return Err(Error::NameMustBeUrlFriendly);
+    }
+
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::validate;
+
+    fn assert_err(name: &str) {
+        let is_valid = validate(&String::from(name));
+
+        if is_valid.is_ok() {
+            panic!("test failed: package name `{name}` passes when it shouldn't")
+        }
+    }
+
+    fn assert_ok(name: &str) {
+        let is_valid = validate(&String::from(name));
+
+        if let Err(e) = is_valid {
+            panic!("test failed: package name `{name}` fails with error: {e}")
+        }
+    }
+
+    #[test]
+    fn accept_valid() {
+        assert_ok("some-package");
+        assert_ok("discord.js");
+        assert_ok("num3ric");
+        assert_ok("under_scores")
+    }
+
+    #[test]
+    fn reject_special_characters() {
+        assert_err("crazy!");
+        assert_err("@npm-zors/money!time.js")
+    }
+
+    #[test]
+    fn accept_scoped() {
+        assert_ok("@custard/hi")
+    }
+
+    #[test]
+    fn reject_zero_len() {
+        assert_err("")
+    }
+
+    #[test]
+    fn reject_name_that_starts_with_period() {
+        assert_err(".start-with-period")
+    }
+
+    #[test]
+    fn reject_name_that_starts_with_underscore() {
+        assert_err("_start-with-underscore")
+    }
+
+    #[test]
+    fn reject_colons_in_name() {
+        assert_err("contain:colons")
+    }
+
+    #[test]
+    fn reject_leading_space() {
+        assert_err(" leading-space")
+    }
+
+    #[test]
+    fn reject_trailing_space() {
+        assert_err("trailing-space ")
+    }
+
+    #[test]
+    fn reject_non_url_friendly() {
+        assert_err("s/l/a/s/h/e/s")
+    }
+
+    #[test]
+    fn reject_blacklisted_name() {
+        assert_err("favicon.ico");
+        assert_err("node_modules")
+    }
+
+    #[test]
+    fn reject_core_modules() {
+        assert_err("http");
+        assert_err("process")
+    }
+
+    #[test]
+    fn accept_max_len() {
+        assert_ok("ifyouwanttogetthesumoftwonumberswherethosetwonumbersarechosenbyfindingthelargestoftwooutofthreenumbersandsquaringthemwhichismultiplyingthembyitselfthenyoushouldinputthreenumbersintothisfunctionanditwilldothatforyou")
+    }
+
+    #[test]
+    fn reject_mixed_case() {
+        assert_err("hello-WORLD")
+    }
+
+    #[test]
+    fn reject_name_over_max_len() {
+        assert_err("ifyouwanttogetthesumoftwonumberswherethosetwonumbersarechosenbyfindingthelargestoftwooutofthreenumbersandsquaringthemwhichismultiplyingthembyitselfthenyoushouldinputthreenumbersintothisfunctionanditwilldothatforyoucool")
+    }
+
+    #[test]
+    fn reject_empty() {
+        assert_err("")
+    }
+}