Stacked bar with JUnit style records - vega

Question

I have a dataset exported from a JUnitXML file and I would like to create a simple visualisation using Vega-lite of a stacked bar for each test suite. The problem is that in JUnit style you don't get a value for "success" but instead you get a "tests" fields that is the sum of all types of tests.
So far I've just naively exported as tidy data and then mapped to x, y and color.
Current visualisation
Vega-editor
{
"$schema": "https://vega.github.io/schema/vega-lite/v4.json",
"data": {"name": "results"},
"mark": "bar",
"encoding": {
"y": {"field": "name", "type": "nominal"},
"x": {"aggregate": "sum", "field": "count", "type": "quantitative", "stack": "normalize"},
"color": {"field": "type"}
},
"datasets": {
"results": [
{"name": "test_suite_0", "type": "tests", "count": 10},
{"name": "test_suite_1", "type": "tests", "count": 10},
{"name": "test_suite_2", "type": "tests", "count": 10},
{"name": "test_suite_3", "type": "tests", "count": 10},
{"name": "test_suite_4", "type": "tests", "count": 10},
{"name": "general-test-suite", "type": "tests", "count": 10},
{"name": "test_suite_0", "type": "skipped", "count": 2},
{"name": "test_suite_1", "type": "skipped", "count": 2},
{"name": "test_suite_2", "type": "skipped", "count": 3},
{"name": "test_suite_3", "type": "skipped", "count": 4},
{"name": "test_suite_4", "type": "skipped", "count": 3},
{"name": "general-test-suite", "type": "skipped", "count": 1},
{"name": "test_suite_0", "type": "failures", "count": 3},
{"name": "test_suite_1", "type": "failures", "count": 2},
{"name": "test_suite_2", "type": "failures", "count": 0},
{"name": "test_suite_3", "type": "failures", "count": 2},
{"name": "test_suite_4", "type": "failures", "count": 3},
{"name": "general-test-suite", "type": "failures", "count": 3},
{"name": "test_suite_0", "type": "errors", "count": 4},
{"name": "test_suite_1", "type": "errors", "count": 4},
{"name": "test_suite_2", "type": "errors", "count": 4},
{"name": "test_suite_3", "type": "errors", "count": 1},
{"name": "test_suite_4", "type": "errors", "count": 4},
{"name": "general-test-suite", "type": "errors", "count": 2}
]
}
}
I would like to change the tests values for success, which should be the difference of tests-(sum of count of other fields grouped by name) but I have no clue about how to do it.

Answer 1

You could use an aggregate transform followed by a calculate transform; something like this (vega editor):
{
"data": {"name": "results"},
"transform": [
{
"aggregate": [
{"op": "sum", "field": "count", "as": "total"},
{"op": "max", "field": "count", "as": "tests"}
],
"groupby": ["name"]
},
{"calculate": "2 * datum.tests - datum.total", "as": "passed"}
],
"mark": "bar",
"encoding": {
"x": {"type": "quantitative", "field": "passed"},
"y": {"type": "nominal", "field": "name"}
},
"datasets": {
"results": [
{"count": 10, "name": "test_suite_0", "type": "tests"},
{"count": 10, "name": "test_suite_1", "type": "tests"},
{"count": 10, "name": "test_suite_2", "type": "tests"},
{"count": 10, "name": "test_suite_3", "type": "tests"},
{"count": 10, "name": "test_suite_4", "type": "tests"},
{"count": 10, "name": "general-test-suite", "type": "tests"},
{"count": 2, "name": "test_suite_0", "type": "skipped"},
{"count": 2, "name": "test_suite_1", "type": "skipped"},
{"count": 3, "name": "test_suite_2", "type": "skipped"},
{"count": 4, "name": "test_suite_3", "type": "skipped"},
{"count": 3, "name": "test_suite_4", "type": "skipped"},
{"count": 1, "name": "general-test-suite", "type": "skipped"},
{"count": 3, "name": "test_suite_0", "type": "failures"},
{"count": 2, "name": "test_suite_1", "type": "failures"},
{"count": 0, "name": "test_suite_2", "type": "failures"},
{"count": 2, "name": "test_suite_3", "type": "failures"},
{"count": 3, "name": "test_suite_4", "type": "failures"},
{"count": 3, "name": "general-test-suite", "type": "failures"},
{"count": 4, "name": "test_suite_0", "type": "errors"},
{"count": 4, "name": "test_suite_1", "type": "errors"},
{"count": 4, "name": "test_suite_2", "type": "errors"},
{"count": 1, "name": "test_suite_3", "type": "errors"},
{"count": 4, "name": "test_suite_4", "type": "errors"},
{"count": 2, "name": "general-test-suite", "type": "errors"}
]
}
}

Answer 2

I finally got the result I was after (and realised that it's not as pretty as I imagined it). I decided to pivot the columns, calculate the amount of "passed" per test suite and then fold again for easy plotting:
Vega-editor
{
"data": {"name": "results"},
"transform": [
{"pivot": "type", "groupby": ["name"], "value": "count"},
{
"calculate": "datum.tests - (datum.failures + datum.skipped + datum.errors)",
"as": "passed"
},
{
"fold": ["passed", "failures", "skipped", "errors"],
"as": ["type", "count"]
}
],
"mark": "bar",
"encoding": {
"x": {"aggregate": "sum", "type": "quantitative", "field": "count"},
"y": {"type": "nominal", "field": "name"},
"color": {
"type": "nominal",
"field": "type",
"sort": ["passed", "failures", "skipped", "errors"],
"scale": {"range": ["green", "red", "grey", "yellow"]}
},
"order": {"range": ["passed", "failures", "skipped", "errors"]}
},
"datasets": {
"results": [
{"count": 10, "name": "test_suite_0", "type": "tests"},
{"count": 10, "name": "test_suite_1", "type": "tests"},
{"count": 10, "name": "test_suite_2", "type": "tests"},
{"count": 10, "name": "test_suite_3", "type": "tests"},
{"count": 10, "name": "test_suite_4", "type": "tests"},
{"count": 10, "name": "general-test-suite", "type": "tests"},
{"count": 2, "name": "test_suite_0", "type": "skipped"},
{"count": 2, "name": "test_suite_1", "type": "skipped"},
{"count": 3, "name": "test_suite_2", "type": "skipped"},
{"count": 4, "name": "test_suite_3", "type": "skipped"},
{"count": 3, "name": "test_suite_4", "type": "skipped"},
{"count": 1, "name": "general-test-suite", "type": "skipped"},
{"count": 3, "name": "test_suite_0", "type": "failures"},
{"count": 2, "name": "test_suite_1", "type": "failures"},
{"count": 0, "name": "test_suite_2", "type": "failures"},
{"count": 2, "name": "test_suite_3", "type": "failures"},
{"count": 3, "name": "test_suite_4", "type": "failures"},
{"count": 3, "name": "general-test-suite", "type": "failures"},
{"count": 4, "name": "test_suite_0", "type": "errors"},
{"count": 4, "name": "test_suite_1", "type": "errors"},
{"count": 4, "name": "test_suite_2", "type": "errors"},
{"count": 1, "name": "test_suite_3", "type": "errors"},
{"count": 4, "name": "test_suite_4", "type": "errors"},
{"count": 2, "name": "general-test-suite", "type": "errors"}
]
}
}