Forge Snapshots Analyzer 🧠

Forge Snapshots Analyzer is a bash script designed to compare and analyze snapshots made with forge snapshot. Currently, it supports the comparison of two gas snapshots.

It calculates:

• Total gas saved.
• % of gas saved compared to the original unoptimized code.

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Installation 📦

1️⃣ Ensure the install-forge-snapshot-analyzer.sh is in the same directory as your snapshots.

2️⃣ Grant execution permissions:

chmod +x install-forge-snapshot-analyzer.sh

3️⃣ Execute the installation script:

./install-forge-snapshot-analyzer.sh

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Usage 🚀

After installation, you'll find a new bash script forge-snapshots-analyzer.sh in your directory with execution permissions pre-set.

📓 Note: When executing, make the snapshot of the "optimized" code be the first argument and the snapshot from the non-optimized the second argument.

Execute it with:

./forge-snapshots-analyzer.sh snapshot-optimized snapshot-non-optimized

Additionally, you'll notice a new directory named ./forge-snapshot-analyzer-scripts. This contains all the auxiliary bash scripts that coordinate to analyze your snapshots.

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Snapshots examples in this repo 📸

In this repo, there are a few snapshots examples so you can clone the repo and see how the script functions:

• ⭐ .gas-snapshot: Original snapshot.
• ⭐ .gas-snapshot-optimized: Snapshot with improved gas consumption.
• ⭐ .gas-snapshot-bad-opt: Snapshot where gas consumption did not improve.
• ⭐ .gas-snapshot-equal-opt: Snapshot where individual test consumption changed, but net result was unchanged.

How are the results displayed? 👓

Display examples 🖼️

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If code reults in optimization

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If code doesn't reult in optimization

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If code reults in overall zero improvement

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Internal Workings of Bash Scripts 🛠️

🔧 compare-gas-snapshots.sh

compare-gas-snapshots.sh

it goes row-by-row in a snapshot, comparing the gas(number) value with its counterpart in the second snapshot file. When a fuzz test is found, it extracts the value from the μ:Number. If an invariant test is detected, it defaults the gas consumption to 0 since forge currently doesn't offer gas metrics for such tests.

The results are saved in a .snapshots-compared-results file.

🔧 filter-out-zero-gas-results.sh

filter-out-zero-gas-results.sh

This script checks the output file from compare-gas-snapshots.sh. If there's no difference in gas values between snapshots (i.e., the difference is 0), such results get filtered out. The processed file is named .snapshots-compared-filtered.

🔧 count-total-gas.sh

count-total-gas.sh

It counts and displays the total gas consumption for both snapshots. It also shows the total difference in gas. All this derived from the filter-out-zero-gas-results output file.

🔧 analyze-gas-results.sh

analyze-gas-results.sh

It operates on the file filter-out-zero-gas-results. It calculates:

• Cumulative sum of the last column (gas saved or not in each test).
• Cumulative sum of the penultimate column (original gas consumption).
• Percentage representation: (gasSaved / originalConsumption) * 100.

It then displays the total saved gas and its percentage against the original gas consumption.

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