testing project

4-testing/readme.md

@@ -0,0 +1,36 @@
+# Testing
+Go has a lightweight test framework composed of the go test command and the testing package.
+
+Write a test by creating a file with a name ending in `_test.go` that contains functions named TestXXX with signature `func (t *testing.T)`. The test framework runs each such function; if the function calls a failure function such as t.Error or t.Fail, the test is considered to have failed. 
+
+```bash
+cp -r 3-importremote 4-testing
+# change importremote to testing
+nano go.mod
+nano hello.go
+# create test for reverse
+cd importpackage
+nano reverse_test.go
+>   package morestrings
+>   
+>   import "testing"
+>   
+>   func TestReverseRunes(t *testing.T) {
+>   	cases := []struct {
+>   		in, want string
+>   	}{
+>   		{"Hello, world", "dlrow ,olleH"},
+>   		{"Hello, 世界", "界世 ,olleH"},
+>   		{"", ""},
+>   	}
+>   	for _, c := range cases {
+>   		got := ReverseRunes(c.in)
+>   		if got != c.want {
+>   			t.Errorf("ReverseRunes(%q) == %q, want %q", c.in, got, c.want)
+>   		}
+>   	}
+>   }
+go build
+# run test code
+go test
+```