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package controllers
import (
"testing"
"github.com/stretchr/testify/assert"
)
func Test_calculateLinesToScrollUp(t *testing.T) {
scenarios := []struct {
name string
viewPortStart int
viewPortHeight int
scrollOffMargin int
lineIdxBefore int
lineIdxAfter int
expectedLinesToScroll int
}{
{
name: "before position is above viewport - don't scroll",
viewPortStart: 10,
viewPortHeight: 10,
scrollOffMargin: 3,
lineIdxBefore: 9,
lineIdxAfter: 8,
expectedLinesToScroll: 0,
},
{
name: "before position is below viewport - don't scroll",
viewPortStart: 10,
viewPortHeight: 10,
scrollOffMargin: 3,
lineIdxBefore: 20,
lineIdxAfter: 19,
expectedLinesToScroll: 0,
},
{
name: "before and after positions are outside scroll-off margin - don't scroll",
viewPortStart: 10,
viewPortHeight: 10,
scrollOffMargin: 3,
lineIdxBefore: 14,
lineIdxAfter: 13,
expectedLinesToScroll: 0,
},
{
name: "before outside, after inside scroll-off margin - scroll by 1",
viewPortStart: 10,
viewPortHeight: 10,
scrollOffMargin: 3,
lineIdxBefore: 13,
lineIdxAfter: 12,
expectedLinesToScroll: 1,
},
{
name: "scroll-off margin is zero - scroll by 1 at end of view",
viewPortStart: 10,
viewPortHeight: 10,
scrollOffMargin: 0,
lineIdxBefore: 10,
lineIdxAfter: 9,
expectedLinesToScroll: 1,
},
{
name: "before inside scroll-off margin - scroll by more than 1",
viewPortStart: 10,
viewPortHeight: 10,
scrollOffMargin: 3,
lineIdxBefore: 11,
lineIdxAfter: 10,
expectedLinesToScroll: 3,
},
{
name: "very large scroll-off margin - keep view centered (even viewport height)",
viewPortStart: 10,
viewPortHeight: 10,
scrollOffMargin: 999,
lineIdxBefore: 15,
lineIdxAfter: 14,
expectedLinesToScroll: 1,
},
{
name: "very large scroll-off margin - keep view centered (odd viewport height)",
viewPortStart: 10,
viewPortHeight: 9,
scrollOffMargin: 999,
lineIdxBefore: 14,
lineIdxAfter: 13,
expectedLinesToScroll: 1,
},
}
for _, scenario := range scenarios {
t.Run(scenario.name, func(t *testing.T) {
linesToScroll := calculateLinesToScrollUp(scenario.viewPortStart, scenario.viewPortHeight, scenario.scrollOffMargin, scenario.lineIdxBefore, scenario.lineIdxAfter)
assert.Equal(t, scenario.expectedLinesToScroll, linesToScroll)
})
}
}
func Test_calculateLinesToScrollDown(t *testing.T) {
scenarios := []struct {
name string
viewPortStart int
viewPortHeight int
scrollOffMargin int
lineIdxBefore int
lineIdxAfter int
expectedLinesToScroll int
}{
{
name: "before position is above viewport - don't scroll",
viewPortStart: 10,
viewPortHeight: 10,
scrollOffMargin: 3,
lineIdxBefore: 9,
lineIdxAfter: 10,
expectedLinesToScroll: 0,
},
{
name: "before position is below viewport - don't scroll",
viewPortStart: 10,
viewPortHeight: 10,
scrollOffMargin: 3,
lineIdxBefore: 20,
lineIdxAfter: 21,
expectedLinesToScroll: 0,
},
{
name: "before and after positions are outside scroll-off margin - don't scroll",
viewPortStart: 10,
viewPortHeight: 10,
scrollOffMargin: 3,
lineIdxBefore: 15,
lineIdxAfter: 16,
expectedLinesToScroll: 0,
},
{
name: "before outside, after inside scroll-off margin - scroll by 1",
viewPortStart: 10,
viewPortHeight: 10,
scrollOffMargin: 3,
lineIdxBefore: 16,
lineIdxAfter: 17,
expectedLinesToScroll: 1,
},
{
name: "scroll-off margin is zero - scroll by 1 at end of view",
viewPortStart: 10,
viewPortHeight: 10,
scrollOffMargin: 0,
lineIdxBefore: 19,
lineIdxAfter: 20,
expectedLinesToScroll: 1,
},
{
name: "before inside scroll-off margin - scroll by more than 1",
viewPortStart: 10,
viewPortHeight: 10,
scrollOffMargin: 3,
lineIdxBefore: 18,
lineIdxAfter: 19,
expectedLinesToScroll: 3,
},
{
name: "very large scroll-off margin - keep view centered (even viewport height)",
viewPortStart: 10,
viewPortHeight: 10,
scrollOffMargin: 999,
lineIdxBefore: 15,
lineIdxAfter: 16,
expectedLinesToScroll: 1,
},
{
name: "very large scroll-off margin - keep view centered (odd viewport height)",
viewPortStart: 10,
viewPortHeight: 9,
scrollOffMargin: 999,
lineIdxBefore: 14,
lineIdxAfter: 15,
expectedLinesToScroll: 1,
},
}
for _, scenario := range scenarios {
t.Run(scenario.name, func(t *testing.T) {
linesToScroll := calculateLinesToScrollDown(scenario.viewPortStart, scenario.viewPortHeight, scenario.scrollOffMargin, scenario.lineIdxBefore, scenario.lineIdxAfter)
assert.Equal(t, scenario.expectedLinesToScroll, linesToScroll)
})
}
}
|
