TENET: Leveraging Tests Beyond Validation for Code Generation
Authors: name: Yiran Hu; name: Nan Jiang; name: Shanchao Liang; name: Yi Wu; name: Lin Tan
Published: 2025-09-29 00:53:16

Abstract: Test-Driven Development (TDD) is a widely adopted software engineering
practice that requires developers to create and execute tests alongside code
implementation, ensuring that software behavior is continuously validated and
refined. In the era of vibe coding, where developers increasingly delegate code
writing to large language models (LLMs) by specifying high-level intentions,
TDD becomes even more crucial, as test cases serve as executable specifications
that explicitly define and verify intended functionality beyond what
natural-language descriptions and code context can convey. While vibe coding
under TDD is promising, there are three main challenges: (1) selecting a small
yet effective test suite to improve the generation accuracy and control the
execution workload, (2) retrieving context such as relevant code effectively,
and (3) systematically using test feedback for effective code refinement. To
address these challenges, we introduce TENET, an LLM agent for generating
functions in complex real-world repositories under the TDD setting. TENET
features three components: (1) a novel test harness mechanism that selects a
concise test suite to maximize diversity of target usage scenarios; (2) a
tailored agent toolset that performs efficient retrieval of relevant code with
interactive debugging; and (3) a reflection-based refinement workflow that
iteratively analyzes failures, replenishes context, and applies code
refinement. TENET achieves 69.08% and 81.77% Pass@1 on RepoCod and RepoEval
benchmarks, outperforming the best agentic baselines by 9.49 and 2.17
percentage points, respectively. In addition, this is the first study of
test-driven code generation with repository-level context, examining how
different aspects of test suites affect the performance of LLM agents under the
TDD setting.