initial os release. I really expect SO much bugs, guys. good luck =)

sabry_intrnl/src/scoper/hash.rs

@@ -0,0 +1,97 @@
+use base64::Engine;
+
+use crate::config::SabryHashConfig;
+
+use super::ArbitraryScope;
+
+/// Convenience wrapper for String-being-a-hash
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct ScopeHash(String);
+
+impl ScopeHash {
+    pub fn new(scope: &ArbitraryScope, config: &SabryHashConfig) -> Self {
+        let mut hasher = blake3::Hasher::new();
+
+        if config.use_scope_name {
+            hasher.update(scope.name.to_string().as_bytes());
+        }
+        if config.use_code_text {
+            hasher.update(scope.adapter().source().as_bytes());
+        }
+        if config.use_code_size {
+            hasher.update(&scope.adapter().source().len().to_ne_bytes());
+        }
+        if config.use_item_names {
+            let classes = scope.adapter().class_selectors();
+            let ids = scope.adapter().id_selectors();
+            //# types/tags dont participate
+            //# child-parent dont participate
+
+            let merged_items = classes
+                .iter()
+                .map(|s| &s.name)
+                .chain(ids.iter().map(|i| &i.name))
+                .map(|ident| ident.as_literal())
+                .filter_map(|mbl| mbl.map(|l| l.raw))
+                .collect::<String>();
+
+            hasher.update(merged_items.as_bytes());
+        }
+
+        let size = if config.size >= blake3::OUT_LEN {
+            blake3::OUT_LEN
+        } else {
+            config.size
+        };
+
+        let hash = hasher.finalize();
+        let hash = hash.as_bytes();
+
+        //? This isn't right. "size" is size of hash in symbols.
+        // naaah, its fine :D (Dan)
+        let hash = base64::prelude::BASE64_URL_SAFE_NO_PAD.encode(&hash[..size]);
+
+        Self(hash)
+    }
+
+    pub fn as_str(&self) -> &str {
+        &self.0
+    }
+
+    #[cfg(test)]
+    pub fn test_init(v: String) -> Self {
+        Self(v)
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use syn::Ident;
+
+    use crate::{config::SabryHashConfig, scoper::ArbitraryScope};
+
+    use super::ScopeHash;
+
+    #[test]
+    fn hash_matches() {
+        let source = ".cls1{color:red; &-dark{color: black} #id1 {color:green;} div {color:blue;}} .cls3#id2{color: black;}";
+
+        let scope1 = ArbitraryScope::from_source(
+            raffia::Syntax::Scss,
+            syn::parse_str::<Ident>("lasifudm").unwrap(),
+            source,
+        )
+        .unwrap();
+        let hash1 = ScopeHash::new(&scope1, &SabryHashConfig::default());
+
+        let scope2 = ArbitraryScope::from_source(
+            raffia::Syntax::Scss,
+            syn::parse_str::<Ident>("lasifudm").unwrap(),
+            source,
+        )
+        .unwrap();
+        let hash2 = ScopeHash::new(&scope2, &SabryHashConfig::default());
+
+        assert_eq!(hash1, hash2);
+    }
+}