adt: add tests for IntervalTree.Find()

[redwrasse]

Adds tests for IntervalTree.Find(), following up on #19768 (comment) as part of #19769.

cc @serathius

[k8s-ci-robot]

Hi @redwrasse. Thanks for your PR.

I'm waiting for a etcd-io member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[serathius]

Was looking for something more extensive. Quick prompt to ML gave me the following results:

func TestIntervalTreeFind(t *testing.T) {
	t.Run("Basic Find Operations", func(t *testing.T) {
		ivt := NewIntervalTree()
		ivl1 := NewInt64Interval(3, 6)
		val1 := 123

		// 1. Find on empty tree
		assert.Nil(t, ivt.Find(ivl1), "Find on empty tree should return nil")

		// 2. Insert and find exact match
		ivt.Insert(ivl1, val1)
		foundNode := ivt.Find(ivl1)
		assert.NotNil(t, foundNode, "Find should return the inserted interval")
		if foundNode != nil {
			assert.Equal(t, ivl1, foundNode.Ivl, "Found interval should match the inserted interval")
			assert.Equal(t, val1, foundNode.Val, "Found value should match the inserted value")
		}

		// 3. Find non-existent interval (overlapping start, different end)
		ivl2 := NewInt64Interval(3, 7)
		assert.Nil(t, ivt.Find(ivl2), "Find should return nil for an interval not exactly matching (different end)")

		// 4. Find non-existent interval (overlapping end, different start)
		ivl3 := NewInt64Interval(2, 6)
		assert.Nil(t, ivt.Find(ivl3), "Find should return nil for an interval not exactly matching (different start)")

		// 5. Find non-existent interval (completely different)
		ivl4 := NewInt64Interval(10, 20)
		assert.Nil(t, ivt.Find(ivl4), "Find should return nil for a completely different interval")

		// 6. Insert another interval and find both
		ivl5 := NewInt64Interval(10, 15)
		val5 := 456
		ivt.Insert(ivl5, val5)

		foundNode1 := ivt.Find(ivl1)
		assert.NotNil(t, foundNode1)
		if foundNode1 != nil {
			assert.Equal(t, ivl1, foundNode1.Ivl)
			assert.Equal(t, val1, foundNode1.Val)
		}

		foundNode5 := ivt.Find(ivl5)
		assert.NotNil(t, foundNode5)
		if foundNode5 != nil {
			assert.Equal(t, ivl5, foundNode5.Ivl)
			assert.Equal(t, val5, foundNode5.Val)
		}
	})

	t.Run("Find After Deletion", func(t *testing.T) {
		ivt := NewIntervalTree()
		ivlA := NewInt64Interval(1, 5)
		valA := "A"
		ivlB := NewInt64Interval(6, 10)
		valB := "B"

		ivt.Insert(ivlA, valA)
		ivt.Insert(ivlB, valB)

		assert.NotNil(t, ivt.Find(ivlA), "Should find ivlA before deletion")
		assert.NotNil(t, ivt.Find(ivlB), "Should find ivlB before deletion")

		deleted := ivt.Delete(ivlA)
		assert.True(t, deleted, "Delete should return true for an existing interval")
		assert.Nil(t, ivt.Find(ivlA), "Should not find ivlA after deletion")
		assert.NotNil(t, ivt.Find(ivlB), "Should still find ivlB after deleting ivlA")

		deleted = ivt.Delete(NewInt64Interval(100, 200)) // Non-existent
		assert.False(t, deleted, "Delete should return false for a non-existing interval")
	})

	t.Run("Find with StringComparable", func(t *testing.T) {
		ivt := NewIntervalTree()
		sivl1 := NewStringInterval("apple", "banana")
		sval1 := "fruit1"

		assert.Nil(t, ivt.Find(sivl1), "Find on empty string tree should return nil")

		ivt.Insert(sivl1, sval1)
		foundNode := ivt.Find(sivl1)
		assert.NotNil(t, foundNode, "Find should return the inserted string interval")
		if foundNode != nil {
			assert.Equal(t, sivl1, foundNode.Ivl)
			assert.Equal(t, sval1, foundNode.Val)
		}

		sivl2 := NewStringInterval("apple", "cherry") // Different end
		assert.Nil(t, ivt.Find(sivl2), "Find should return nil for a non-exact string interval")
	})

    t.Run("Find with overlapping but not identical intervals", func(t *testing.T) {
        ivt := NewIntervalTree()
        ivlBase := NewInt64Interval(5, 10)
        valBase := "base"
        ivt.Insert(ivlBase, valBase)

        // Test cases that overlap but are not identical
        testCases := []struct {
            name     string
            interval Interval
        }{
            {"Subset", NewInt64Interval(6, 9)},
            {"Superset", NewInt64Interval(4, 11)},
            {"OverlapLeft", NewInt64Interval(3, 7)},
            {"OverlapRight", NewInt64Interval(8, 12)},
            {"TouchesBegin", NewInt64Interval(3, 5)}, // Does not overlap [5,10)
            {"TouchesEnd", NewInt64Interval(10, 12)}, // Does not overlap [5,10)
        }

        for _, tc := range testCases {
            t.Run(tc.name, func(t *testing.T) {
                assert.Nil(t, ivt.Find(tc.interval), "Find(%v) should be nil as it's not an exact match for %v", tc.interval, ivlBase)
            })
        }
         // Ensure the base interval is still findable
        foundNode := ivt.Find(ivlBase)
        assert.NotNil(t, foundNode)
        if foundNode != nil {
            assert.Equal(t, ivlBase, foundNode.Ivl)
        }
    })
}

[redwrasse]

Ok I've expanded TestIntervalTreeFind with a couple workflows along the above code sample. Also checking Find is nil after Delete in TestIntervalTreeRandom.

Let me know if there's more specific cases I should include. Trying to keep the test style +coverage consistent with the rest of interval_tree_test.go.

[serathius]

/ok-to-test

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: redwrasse, serathius

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [serathius]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[serathius]

/retest

[k8s-ci-robot]

@redwrasse: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
pull-etcd-coverage-report	abf0439	link	true	/test pull-etcd-coverage-report

Full PR test history. Your PR dashboard. Please help us cut down on flakes by linking to an open issue when you hit one in your PR.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository. I understand the commands that are listed here.