| Name | Lines of code | Maintainability | Test coverage |
| src/SpelExpressionEvaluator.js | 30 | A 0 mins | |
| src/ast/VariableReference.js | 32 | A 1 hr | |
| webpack.config.babel.js | 34 | A 0 mins | |
| src/ast/Projection.js | 34 | A 1 hr | |
| src/ast/FunctionReference.js | 34 | B 4 hrs | |
| src/ast/Indexer.js | 34 | A 1 hr | |
| src/ast/ConstructorReference.js | 42 | B 6 hrs | |
| src/ast/CompoundExpression.js | 47 | A 2 hrs | |
| src/Token.js | 48 | A 0 mins | |
| src/ast/PropertyReference.js | 49 | A 4 hrs | |
| src/ast/MethodReference.js | 64 | C 1 day | |
| src/ast/SpelNode.js | 78 | B 4 hrs | |
| src/TokenKind.js | 82 | A 0 mins | |
| src/ast/Selection.js | 86 | A 3 hrs | |
| src/Tokenizer.js | 495 | F 1 wk | |
| src/SpelExpressionParser.js | 784 | F 2 wks |