Implement table.

src/wasm_test/compare.rs

@@ -1,4 +1,6 @@
+use std::borrow::Borrow;
 use std::borrow::Cow;
+use std::collections::BTreeSet;
 use std::collections::HashMap;
 
 use super::diff::WasmDiffResult;
@@ -58,6 +60,10 @@ fn compare_json_value<'b, 's>(
             // We hit an object tree additional property.
             compare_number_lines(source, el, wasm)
         }
+        (serde_json::Value::Object(wasm), Token::List(el)) if wasm.contains_key("string-set") => {
+            // We hit an object tree additional property.
+            compare_string_set(source, el, wasm)
+        }
         (serde_json::Value::Object(w), Token::TextWithProperties(e)) if is_plain_text(w) => {
             compare_plain_text(source, e, w)
         }
@@ -719,6 +725,50 @@ fn compare_number_lines<'e, 's, 'w>(
     Ok(result)
 }
 
+fn compare_string_set<'e, 's, 'w>(
+    source: &'s str,
+    emacs: &'e Vec<Token<'s>>,
+    wasm: &'w serde_json::Map<String, serde_json::Value>,
+) -> Result<WasmDiffResult<'s>, Box<dyn std::error::Error>> {
+    let mut result = WasmDiffResult::default();
+    let wasm_list = wasm
+        .get("value")
+        .ok_or(r#"Wasm string set should have a "value" attribute."#)?
+        .as_array()
+        .ok_or(r#"Wasm string set "value" attribute should be a list."#)?;
+    let wasm_strings = wasm_list
+        .iter()
+        .map(|v| v.as_str().ok_or("Non-string in wasm string set."))
+        .collect::<Result<BTreeSet<_>, &'static str>>()?;
+    let emacs_strings = emacs
+        .iter()
+        .map(|v| v.as_atom())
+        .collect::<Result<Vec<_>, Box<dyn std::error::Error>>>()?
+        .into_iter()
+        .map(|s| unquote(s))
+        .collect::<Result<Vec<_>, Box<dyn std::error::Error>>>()?;
+    let emacs_strings = emacs_strings
+        .iter()
+        .map(|s| s.borrow())
+        .collect::<BTreeSet<&str>>();
+
+    let mismatched: Vec<_> = emacs_strings
+        .symmetric_difference(&wasm_strings)
+        .copied()
+        .collect();
+    if !mismatched.is_empty() {
+        result.status.push(WasmDiffStatus::Bad(
+            format!(
+                "String set mismatch. MismatchedValues=({values:?}).",
+                values = mismatched.join(", ")
+            )
+            .into(),
+        ));
+    }
+
+    Ok(result)
+}
+
 fn is_plain_text<'e, 's, 'w>(wasm: &'w serde_json::Map<String, serde_json::Value>) -> bool {
     if let Some(serde_json::Value::String(node_type)) = wasm.get("ast-node") {
         node_type == "plain-text"