Understanding Ethereum test logs with Foundry: μ (number of consecutive matches) and ~ (relative position)
Since you see a noticeable number of “runs” in the Foundry test logs, we will look at the value of two important metrics: μ and ~.
μ (μ): number of consecutive matches
μ represents the number of times a certain event or condition is triggered during the specified time period. In the context of testing Ethereum smart contracts on Foundry, μ often corresponds to the frequency of successful deployments or function calls over a certain period.
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Example:
– The test case can have μ = 100, which indicates that the deployed smart contract has successfully released a certain function at least 100 times during the specified time period.
~ (relative position)
~ indicates the relative position of the event in the test logs. In Ethereum development, it is used to describe how far a particular test case or function call is within the expected range.
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Example:
– The test could start with the index 0 and end with the index 100 for a certain function of the smart contract. If the function was called approximately 93 times during this period, the value of ~ will be equal to 93.
Interpretation of μ and ~ in Foundry test logs
To accurately interpret your logs, consider the following:
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Values of μ:
– High values (for example, 100) may indicate that the smart contract function is constantly called at the expected time.
– Low values (for example, 10) may indicate that a particular function call is not occurring as often as expected.
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~ Values:
– Positive ~ values (for example, 93) indicate that the test case or function call is moving toward the expected range.
– Negative ~ values (for example, -10) may indicate that the event deviates from the expected range, possibly due to problems with the testing logic.
Best practices for finding μ and ~ values
To ensure an accurate interpretation of Ethereum test logs on Foundry:
- Understand your test case: Study the specific smart contract feature being tested.
- Read μ and ~: Learn how these metrics are calculated in various Ethereum development frameworks, including Foundry.
- Watch your logs carefully:
Watch your logs carefully for any deviations from expected values.
By understanding μ (number of consecutive matches) and ~ (relative position), you will be better prepared to diagnose problems with smart contract testing on Foundry or to optimize testing strategies to achieve more accurate results.