implement builtin fn map.deep-remove

.gitignore

@@ -36,3 +36,4 @@ dart-sass
 sass-fairy
 duomo
 ibm-cloud-cognitive
+pico

CHANGELOG.md

@@ -9,7 +9,7 @@
 
 # TBD
 
-- implement builtin map-module function `map.deep-merge(..)`
+- implement builtin map-module functions `map.deep-merge(..)` and `map.deep-remove(..)`
 
 # 0.12.3
 

README.md

@@ -84,10 +84,10 @@ The spec runner does not work on Windows.
 Using a modified version of the spec runner that ignores warnings and error spans (but does include error messages), `grass` achieves the following results:
 
 ```
-2022-01-31
-PASSING: 6248
-FAILING: 624
-TOTAL: 6892
+2022-05-11
+PASSING: 6277
+FAILING: 596
+TOTAL: 6905
 ```
 
 The majority of the failing tests are purely aesthetic, relating to whitespace

crates/compiler/src/builtin/modules/map.rs

@@ -1,3 +1,5 @@
+use std::iter::Peekable;
+
 use crate::builtin::builtin_imports::*;
 
 use crate::builtin::{
@@ -16,9 +18,7 @@ fn deep_merge_impl(map1: SassMap, map2: SassMap) -> SassMap {
     let mut result = map1;
 
     for (key, value) in map2 {
-        let result_map = result.get_ref(&key.node).and_then(Value::try_map);
-
-        match result_map {
+        match result.get_ref(&key.node).and_then(Value::try_map) {
             Some(result_map) => match value.try_map() {
                 Some(value_map) => {
                     let merged = deep_merge_impl(result_map, value_map);
@@ -53,6 +53,92 @@ fn deep_merge(mut args: ArgumentResult, _: &mut Visitor) -> SassResult<Value> {
     Ok(Value::Map(deep_merge_impl(map1, map2)))
 }
 
+fn deep_remove(mut args: ArgumentResult, _: &mut Visitor) -> SassResult<Value> {
+    let span = args.span();
+
+    let map = args.get_err(0, "map")?.assert_map_with_name("map", span)?;
+
+    let key = args.get_err(1, "key")?;
+    let keys = args.get_variadic()?.into_iter().map(|arg| arg.node);
+    let mut keys = std::iter::once(key).chain(keys).collect::<Vec<_>>();
+
+    let last = keys.pop();
+
+    let map = modify_map(
+        map,
+        keys.into_iter(),
+        |value| {
+            let last = match last.as_ref() {
+                Some(v) => v,
+                None => return value,
+            };
+
+            match value.try_map() {
+                Some(mut nested_map) if nested_map.contains(last) => {
+                    nested_map.remove(last);
+                    Value::Map(nested_map)
+                }
+                Some(..) | None => value,
+            }
+        },
+        false,
+        span,
+    );
+
+    Ok(map)
+}
+
+fn modify_map(
+    map: SassMap,
+    keys: impl Iterator<Item = Value>,
+    modify: impl Fn(Value) -> Value,
+    // default=true
+    add_nesting: bool,
+    span: Span,
+) -> Value {
+    let mut keys = keys.peekable();
+    fn modify_nested_map(
+        mut mutable_map: SassMap,
+        mut keys: Peekable<impl Iterator<Item = Value>>,
+        add_nesting: bool,
+        span: Span,
+        modify: impl Fn(Value) -> Value,
+    ) -> SassMap {
+        let key = keys.next().unwrap();
+
+        if keys.peek().is_none() {
+            let value = modify(mutable_map.get_ref(&key).cloned().unwrap_or(Value::Null));
+            mutable_map.insert(key.span(span), value);
+            return mutable_map;
+        }
+
+        let nested_map = mutable_map.get_ref(&key).and_then(|v| v.try_map());
+
+        if nested_map.is_none() && !add_nesting {
+            return mutable_map;
+        }
+
+        mutable_map.insert(
+            key.span(span),
+            Value::Map(modify_nested_map(
+                nested_map.unwrap_or_default(),
+                keys,
+                add_nesting,
+                span,
+                modify,
+            )),
+        );
+
+        mutable_map
+    }
+
+    if keys.peek().is_some() {
+        Value::Map(modify_nested_map(map, keys, add_nesting, span, modify))
+    } else {
+        modify(Value::Map(map))
+    }
+}
+
 pub(crate) fn declare(f: &mut Module) {
     f.insert_builtin("get", map_get);
     f.insert_builtin("has-key", map_has_key);
@@ -62,4 +148,5 @@ pub(crate) fn declare(f: &mut Module) {
     f.insert_builtin("values", map_values);
     f.insert_builtin("set", map_set);
     f.insert_builtin("deep-merge", deep_merge);
+    f.insert_builtin("deep-remove", deep_remove);
 }

crates/compiler/src/value/map.rs

@@ -81,6 +81,10 @@ impl SassMap {
         self.0.into_iter().map(|(.., v)| v).collect()
     }
 
+    pub fn contains(&self, key: &Value) -> bool {
+        self.0.iter().any(|(k, ..)| &k.node == key)
+    }
+
     pub fn as_list(self) -> Vec<Value> {
         self.0
             .into_iter()

crates/lib/tests/map-module.rs

@@ -133,3 +133,30 @@ test!(
     }"#,
     "a {\n  color: (c: (d: e));\n}\n"
 );
+test!(
+    deep_remove_key_dne,
+    r#"@use "sass:map";
+
+    a {
+        color: inspect(map.deep-remove((a: b), 1));
+    }"#,
+    "a {\n  color: (a: b);\n}\n"
+);
+test!(
+    deep_remove_nested_remove,
+    r#"@use "sass:map";
+
+    a {
+        color: inspect(map.deep-remove((c: (d: e)), c, d));
+    }"#,
+    "a {\n  color: (c: ());\n}\n"
+);
+test!(
+    deep_remove_nested_keys_dne,
+    r#"@use "sass:map";
+
+    a {
+        color: inspect(map.deep-remove((c: (d: e)), c, d, e, f, g));
+    }"#,
+    "a {\n  color: (c: (d: e));\n}\n"
+);