testutil

func Diff ¶

func Diff(want, got interface{}) string

Diff prints a unified diff of two complex (possibly circular) datastructures.

func RecEqual ¶

func RecEqual(x, y interface{}, disjoint bool) bool

RecEqual reports whether x and y are "recursively equal", as defined below. This is similar to reflect.DeepEqual, but also considers whether they have the same structure (shared substructure and cycles). Additionally, recEqual is slightly more picky about some types, and and more lenient about others, than DeepEqual is.

• Values of distinct types are never recursively equal. Values of identical type are recursively equal if one of the following is true:

• Boolean, integer and string values are recursively equal if they are equal according to the == operator.

• Arrays are recursively equal if all their corresponding elements are recursively equal.

• Complex numbers are recursively equal if their corresponding real and imaginary parts are recursively equal.

• Floats are recursively equal if they are both NaN, both 0 or both -0; or if they are non-zero and equal according to the == operator.

• Interface values are recursively equal if their contents are recurisvely equal.

• Map values are recursively equal if they have the same length, and their corresponding keys (according to ==) map to recursively equal values AND ADDITIONALY that every occurrence of a map value m1 (i.e., map values derived from the same map literal or make() call) in v1 corresponds to the same map value m2 in v2 (and vice versa). Note that recursive equality for maps with NaN keys is not well-defined.

• Pointer values are recursively equal if they point at recursively equal values AND ADDITIONALLY if every occurence of pointer p1 in v1 corresponds to the same pointer p2 in v2 (and vice versa).

• Slice values are recursively equal if they are both nil or both non-nil, and have the same length, and their corresponding elements are deeply equal.

• Struct values are recursively equal if their corresponding fields (exported and unexported) are recursively equal.

• Func values are recursively equal if they are both nil or if they point to the same location.

Comparison of Channel and unsafe.Pointer values is not implemented; attempting to compare such values will cause a panic.

In addition to the above rules, if disjoint == true then RecEqual will return false any map, pointer, or slice backing pointer value found in v1 also appears in v2.

N.B.: RecEqual does not make any attempt to check the structure of interior pointers (i.e., a pointer pointing at an array element or struct field), or verify their disjointness. This includes in particular the backing array of slices: given

a := []int{0, 0, 0, 0}

then

RecEqual([2][]int{a[0:2], a[0:2]}, [2][]int{a[0:2], a[2:4]}, true)

returns true, as does

RecEqual([2][]int{a[0:2], a[0:2]}, [2][]int{a[0:2], a[2:4]}, false)