add parsing of bools

crates/graphql_artifact_generation/src/generate_artifacts.rs

@@ -210,6 +210,16 @@ pub(crate) fn get_serialized_field_arguments(
                     {indent_1}],\n"
                 )
             }
+            NonConstantValue::Boolean(bool) => {
+                let bool_string = bool.to_string();
+                format!(
+                    "\n\
+                    {indent_1}[\n\
+                    {indent_2}\"{argument_name}\",\n\
+                    {indent_2}\"{{ kind: \"Literal\", value: {bool_string} }},\n\
+                    {indent_1}],\n"
+                )
+            }
         };
 
         s.push_str(&arg_value);

crates/graphql_artifact_generation/src/query_text.rs

@@ -150,5 +150,6 @@ fn serialize_non_constant_value_for_graphql(value: &NonConstantValue) -> String
     match value {
         NonConstantValue::Variable(variable_name) => format!("${}", variable_name),
         NonConstantValue::Integer(int_value) => int_value.to_string(),
+        NonConstantValue::Boolean(bool) => bool.to_string(),
     }
 }

crates/isograph_lang_parser/src/isograph_literal_parse_error.rs

@@ -32,7 +32,7 @@ pub enum IsographLiteralParseError {
         suggested_const_export_name: ScalarFieldName,
     },
 
-    #[error("Expected a valid value, like $foo or 42")]
+    #[error("Expected a valid value, like $foo, 42, true or false")]
     ExpectedNonConstantValue,
 
     #[error("Descriptions are currently disallowed")]
@@ -58,6 +58,9 @@ pub enum IsographLiteralParseError {
         this client field declaration"
     )]
     DuplicateNameOrAlias { name_or_alias: FieldNameOrAlias },
+
+    #[error("Expected a boolean value (true or false).")]
+    ExpectedBoolean,
 }
 
 impl From<LowLevelParseError> for IsographLiteralParseError {

crates/isograph_lang_parser/src/parse_iso_literal.rs

@@ -451,6 +451,22 @@ fn parse_non_constant_value(
             }))
         })?;
 
+        to_control_flow::<_, WithSpan<IsographLiteralParseError>>(|| {
+            let bool = tokens
+                .parse_source_of_kind(IsographLangTokenKind::Identifier)
+                .map_err(|with_span| with_span.map(IsographLiteralParseError::from))?;
+
+            let span = bool.span;
+
+            bool.and_then(|bool| match bool.parse::<bool>() {
+                Ok(b) => Ok(NonConstantValue::Boolean(b)),
+                Err(_) => Err(WithSpan::new(
+                    IsographLiteralParseError::ExpectedBoolean,
+                    span,
+                )),
+            })
+        })?;
+
         ControlFlow::Continue(WithSpan::new(
             IsographLiteralParseError::ExpectedNonConstantValue,
             Span::todo_generated(),

crates/isograph_lang_types/src/client_field_declaration.rs

@@ -250,13 +250,15 @@ impl SelectionFieldArgument {
 pub enum NonConstantValue {
     Variable(VariableName),
     Integer(u64),
+    Boolean(bool),
 }
 
 impl NonConstantValue {
     pub fn reachable_variables(&self) -> Vec<VariableName> {
         match self {
             NonConstantValue::Variable(name) => vec![*name],
             NonConstantValue::Integer(_) => vec![],
+            NonConstantValue::Boolean(_) => vec![],
         }
     }
 
@@ -265,6 +267,7 @@ impl NonConstantValue {
             NonConstantValue::Variable(name) => format!("v_{}", name),
             // l for literal, i.e. this is shared with others
             NonConstantValue::Integer(int_value) => format!("l_{}", int_value),
+            NonConstantValue::Boolean(bool) => format!("l_{}", bool),
         }
     }
 }

crates/isograph_lang_types/src/directives.rs

@@ -152,6 +152,7 @@ impl<'de> Deserializer<'de> for NonConstantValueDeserializer<'de> {
         match self.value {
             NonConstantValue::Variable(_variable) => todo!("Variable?"),
             NonConstantValue::Integer(u_64) => visitor.visit_u64(*u_64),
+            NonConstantValue::Boolean(bool) => visitor.visit_bool(*bool),
         }
     }