go / intermediate
Snippet
Implementing Table-Driven Tests in Go
Table-driven testing is a standard pattern in Go. It uses a slice of anonymous structs defining inputs and expected outputs to clean up test suites and run multiple assertions cleanly.
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package mainimport "testing"func Add(a, b int) int {return a + b}func TestAdd(t *testing.T) {tests := []struct {name stringa, b intexpected int}{{"positive numbers", 2, 3, 5},{"negative numbers", -1, -1, -2},{"mixed numbers", -5, 10, 5},}for _, tc := range tests {t.Run(tc.name, func(t *testing.T) {result := Add(tc.a, tc.b)if result != tc.expected {t.Errorf("Add(%d, %d) = %d; want %d", tc.a, tc.b, result, tc.expected)}})}}
Breakdown
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tests := []struct {
Declares a slice of anonymous structs representing the test cases.
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for _, tc := range tests {
Iterates over each test case in the defined table.
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t.Run(tc.name, func(t *testing.T) {
Runs each test case as a subtest, providing isolated output and independent failure reporting.
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t.Errorf("Add(%d, %d) = %d; want %d", tc.a, tc.b, result, tc.expected)
Logs the failure and marks the test as failed without stopping execution of remaining subtests.