🌳 Branching Tree Technique (BTT)

Paul Berg

Spearbit seminar: Sep 28, 2023

Personal Background

• 👨‍💻 Ethereum developer for 5+ years
• 🐦 Exporting my brain on Twitter @PaulRBerg
• ⏳ Co-founder and Builder at Sablier Labs
• 📈 Sablier: >$1B in cumulative TVL since 2019
• 🚀 Sablier V2: 100% built with Foundry and BTT

😇 How it starts

              
                function test_Foo() external {
                  uint256 x = 42;
                  assertEq(contract.foo(x), x, "value mismatch");
                }
              
            

😵‍💫 How it ends (monolith)

              
                function test_Foo_1() external {
                  // --- snip ---
                }

                function test_Foo_2() external {
                  // --- snip ---
                }

                function test_Foo_3(uint256 arg0) external {
                  // --- snip ---
                }

                function test_Foo_4(uint256 arg0, uint256 arg1) external {
                  // --- snip ---
                }
              
            

Specification Frameworks

Example: whenBranch.tree

              
                WhenBranchTest
                ├── when x is false
                │   └── it should revert
                └── when x is true
                    └── it should return x
					    
            

Example: simpleWhen.t.sol

              
                contract SimpleWhenTest {
                    function test_RevertWhen_XIsFalse() external {
                        // it should revert
                    }

                    function test_WhenXIsTrue() external {
                        // it should return x
                    }
                }
					    
            

Example: simpleWhen.t.sol

              
                contract SimpleWhenTest {
                    function test_RevertWhen_XIsFalse() external {
                        vm.expectRevert("x must not be false");
                        foo.simpleWhen({ x: false });
                    }

                    function test_WhenXIsTrue() external {
                        bool result = foo.simpleWhen({ x: true });
                        assertTrue(result);
                    }
                }
					    
            

🤔 Given or When?

The End

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