D string expression test.

src/ast/mod.rs

@@ -42,6 +42,31 @@ pub mod node {
             Self::new(vec![])
         }
     }
+
+    impl Expression {
+        pub fn unwrap_identifier(&self) -> &Identifier {
+            let primary = self.ternary_expression()
+                .or_expression()
+                .left()
+                .left()
+                .left()
+                .left()
+                .left()
+                .left()
+                .right()
+                .left();
+            match primary {
+                PrimaryExpression::FullyQualifiedName(fqn) => {
+                    if fqn.identifiers().count() == 1 {
+                        fqn.identifiers().next().unwrap()
+                    } else {
+                        panic!()
+                    }
+                }
+                _ => panic!(),
+            }
+        }
+    }
 }
 
 pub mod build {
@@ -56,6 +81,7 @@ pub mod build {
 
     #[cfg(test)]
     mod build_tests {
+        use std::process::id;
         use super::*;
         use crate::parser::DeimosParser;
         use pest::Parser;
@@ -102,5 +128,13 @@ pub mod build {
             assert_eq!(backtick_string.inners().count(), 2);
             assert_eq!(backtick_string.expressions().count(), 1);
         }
+
+        #[test]
+        fn d_string_expression_simple() {
+            let pair = parse(Rule::DStringExpression, "${thing}");
+            let d_string_expression = build_d_string_expression(pair);
+            let identifier = d_string_expression.expression().unwrap_identifier();
+            assert_eq!("thing", identifier.name());
+        }
     }
 }