Calculator Library Verification

Problem/Feature Description

You have updated a shared Python calculator utility that is used across several internal reporting scripts. The update added a calculate dispatcher function that routes operations by name. Before handing the change to an independent reviewer, run the builder-owned verification pass and confirm the claim that all tests pass.

The team uses pytest and a Makefile for their standard verification workflow. Your job is to verify the changes, exercise the real behavior (not just read the code), and produce a complete verification report. The previous version of this library had a silent failure bug where division errors were swallowed — so error path coverage is important.

Output Specification

Produce a file named verification-report.md containing a complete report with all of the following sections:

• Verdict: one of ready for review, needs more work, or blocked (this is the builder's gate before independent review and must not make a ship decision)
• Change Verified: what was tested and confirmed
• Surfaces Exercised: the exact commands or calls used
• Self-Corrections Applied: any cheap, obvious issues you fixed when the task authorized edits (or "none")
• Top Findings: substantive issues left for review, with severity
• Exact Evidence: commands run and output received
• Readiness Gaps: any gaps in test coverage or infrastructure
• Recommended Follow-up: suggested next steps (typically review when the verdict is ready for review)

Input Files

The following files are provided as inputs. Extract them before beginning.

=============== FILE: inputs/calculator.py =============== def add(a, b): return a + b

def subtract(a, b): return a - b

def multiply(a, b): return a * b

def divide(a, b): if b == 0: raise ValueError("Cannot divide by zero") return a / b

def calculate(operation, a, b): ops = { 'add': add, 'subtract': subtract, 'multiply': multiply, 'divide': divide, } if operation not in ops: raise ValueError(f"Unknown operation: {operation}") return ops[operation](a, b)

=============== FILE: inputs/test_calculator.py =============== import pytest import sys import os sys.path.insert(0, os.path.dirname(file)) from calculator import add, subtract, multiply, divide, calculate

def test_add(): assert add(2, 3) == 5

def test_subtract(): assert subtract(5, 3) == 2

def test_multiply(): assert multiply(3, 4) == 12

def test_divide(): assert divide(10, 2) == 5.0

def test_divide_by_zero(): with pytest.raises(ValueError, match="Cannot divide by zero"): divide(5, 0)

def test_calculate_add(): assert calculate('add', 10, 5) == 15

def test_calculate_unknown_op(): with pytest.raises(ValueError, match="Unknown operation"): calculate('modulo', 5, 3)

=============== FILE: inputs/Makefile =============== .PHONY: test verify lint

verify: test

test: cd inputs && python -m pytest test_calculator.py -v

lint: cd inputs && python -m flake8 calculator.py