45 lines
1.2 KiB
Go
45 lines
1.2 KiB
Go
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// 被测契约：持有 nil 指针的 Engine 与裸 nil 等价，构造器必须拦下而不是留到调用时 panic。
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package ephem
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import "testing"
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type nilCheckEngine struct{ offset float64 }
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func (engine *nilCheckEngine) State(target, center Body, jdTDB float64) (pos, vel [3]float64, err error) {
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pos[0] = engine.offset
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return pos, vel, nil
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}
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func (engine *nilCheckEngine) Coverage(target Body) (start, end float64, ok bool) {
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return 0, engine.offset, true
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}
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func TestConstructorsRejectTypedNilEngine(t *testing.T) {
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var typedNil *nilCheckEngine
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cases := map[string]func() error{
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"NewInstance": func() error {
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_, _, err := NewInstance(typedNil).State(Mars, Sun, 2451545)
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return err
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},
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"NewStack": func() error {
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_, _, err := NewInstance(NewStack(typedNil)).State(Mars, Sun, 2451545)
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return err
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},
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}
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for name, call := range cases {
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if err := call(); err == nil {
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t.Errorf("%s: err = nil, want an error", name)
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}
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}
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}
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func TestInstanceKeepsUsableEngine(t *testing.T) {
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pos, _, err := NewInstance(&nilCheckEngine{offset: 7}).State(Mars, Sun, 2451545)
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if err != nil {
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t.Fatalf("State err = %v", err)
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}
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if pos[0] != 7 {
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t.Errorf("pos[0] = %v, want 7", pos[0])
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}
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}
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