{"record":{"id":"fbbe4c2daa854476","repo":"gleam-lang/gleam","slug":"case-with-no-subjects","errorCode":null,"errorMessage":"case with no subjects","messagePattern":"case with no subjects","errorType":"panic","errorClass":null,"httpStatus":null,"severity":"error","filePath":"compiler-core/src/javascript/decision.rs","lineNumber":535,"sourceCode":"        &mut self,\n        arena: &'doc DocumentArena<'a, 'doc>,\n        clause_index: usize,\n    ) -> BodyExpression<'a, 'doc> {\n        // If we are not in a `case` expression, there is no additional code to\n        // execute when a branch matches; we only assign variables bound in the\n        // pattern.\n        let DecisionKind::Case { clauses } = &self.kind else {\n            return BodyExpression::Expressions(EMPTY_DOCUMENT);\n        };\n\n        let clause = &clauses.get(clause_index).expect(\"invalid clause index\");\n        let body = &clause.then;\n\n        if let Some(subject_index) = clause.returned_subject() {\n            let variable = self\n                .assignments\n                .get(subject_index)\n                .expect(\"case with no subjects\")\n                .name();\n\n            BodyExpression::Variable(\n                self.variables\n                    .expression_generator\n                    .wrap_return(arena, variable.to_doc(arena)),\n            )\n        } else {\n            BodyExpression::Expressions(\n                self.variables\n                    .expression_generator\n                    .expression_flattening_blocks(arena, body),\n            )\n        }\n    }\n\n    fn switch(\n        &mut self,","sourceCodeStart":517,"sourceCodeEnd":553,"githubUrl":"https://github.com/gleam-lang/gleam/blob/7e623aa83da3776faee50ca4ab9a6c40124acd95/compiler-core/src/javascript/decision.rs#L517-L553","documentation":"Error \"case with no subjects\" thrown in gleam-lang/gleam.","triggerScenarios":"Thrown at compiler-core/src/javascript/decision.rs:535 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":[],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"7e623aa83da3776faee50ca4ab9a6c40124acd95","analyzedAt":"2026-08-17T00:07:02.091Z","schemaVersion":2},"datasetVersion":"2026-08-17T04:17:16.089Z"}