From 13c37991d73035c78a0e759260ba9e682d6b0e12 Mon Sep 17 00:00:00 2001
From: Aliaksandr Valialkin <valyala@victoriametrics.com>
Date: Tue, 21 May 2024 13:27:34 +0200
Subject: [PATCH] wip

---
 lib/logstorage/stats_avg_test.go | 386 +++++++++++++++++++++++++++++++
 1 file changed, 386 insertions(+)
 create mode 100644 lib/logstorage/stats_avg_test.go

diff --git a/lib/logstorage/stats_avg_test.go b/lib/logstorage/stats_avg_test.go
new file mode 100644
index 000000000..98c28723f
--- /dev/null
+++ b/lib/logstorage/stats_avg_test.go
@@ -0,0 +1,386 @@
+package logstorage
+
+import (
+	"testing"
+)
+
+func TestParseStatsAvgSuccess(t *testing.T) {
+	f := func(pipeStr string) {
+		t.Helper()
+		expectParseStatsFuncSuccess(t, pipeStr)
+	}
+
+	f(`avg(*)`)
+	f(`avg(a)`)
+	f(`avg(a, b)`)
+}
+
+func TestParseStatsAvgFailure(t *testing.T) {
+	f := func(pipeStr string) {
+		t.Helper()
+		expectParseStatsFuncFailure(t, pipeStr)
+	}
+
+	f(`avg`)
+	f(`avg(a b)`)
+	f(`avg(x) y`)
+}
+
+func TestStatsAvg(t *testing.T) {
+	f := func(pipeStr string, rows, rowsExpected [][]Field) {
+		t.Helper()
+		expectPipeResults(t, pipeStr, rows, rowsExpected)
+	}
+
+	f("stats avg(*) as x", [][]Field{
+		{
+			{"_msg", `abc`},
+			{"a", `2`},
+			{"b", `3`},
+		},
+		{
+			{"_msg", `def`},
+			{"a", `1`},
+		},
+		{
+			{"a", `3`},
+			{"b", `54`},
+		},
+	}, [][]Field{
+		{
+			{"x", "12.6"},
+		},
+	})
+
+	f("stats avg(a) as x", [][]Field{
+		{
+			{"_msg", `abc`},
+			{"a", `2`},
+			{"b", `3`},
+		},
+		{
+			{"_msg", `def`},
+			{"a", `1`},
+		},
+		{
+			{"a", `3`},
+			{"b", `54`},
+		},
+	}, [][]Field{
+		{
+			{"x", "2"},
+		},
+	})
+
+	f("stats avg(a) as a", [][]Field{
+		{
+			{"_msg", `abc`},
+			{"a", `2`},
+			{"b", `3`},
+		},
+		{
+			{"_msg", `def`},
+			{"a", `1`},
+		},
+		{
+			{"a", `3`},
+			{"b", `54`},
+		},
+	}, [][]Field{
+		{
+			{"a", "2"},
+		},
+	})
+
+	f("stats avg(a, b) as x", [][]Field{
+		{
+			{"_msg", `abc`},
+			{"a", `2`},
+			{"b", `3`},
+		},
+		{
+			{"_msg", `def`},
+			{"a", `1`},
+		},
+		{
+			{"a", `3`},
+			{"b", `54`},
+		},
+	}, [][]Field{
+		{
+			{"x", "12.6"},
+		},
+	})
+
+	f("stats avg(b) as x", [][]Field{
+		{
+			{"_msg", `abc`},
+			{"a", `2`},
+			{"b", `3`},
+		},
+		{
+			{"_msg", `def`},
+			{"a", `1`},
+		},
+		{
+			{"a", `3`},
+			{"b", `54`},
+		},
+	}, [][]Field{
+		{
+			{"x", "28.5"},
+		},
+	})
+
+	f("stats avg(c) as x", [][]Field{
+		{
+			{"_msg", `abc`},
+			{"a", `2`},
+			{"b", `3`},
+		},
+		{
+			{"_msg", `def`},
+			{"a", `1`},
+		},
+		{
+			{"a", `3`},
+			{"b", `54`},
+		},
+	}, [][]Field{
+		{
+			{"x", "NaN"},
+		},
+	})
+
+	f("stats avg(a) if (b:*) as x", [][]Field{
+		{
+			{"_msg", `abc`},
+			{"a", `2`},
+			{"b", `3`},
+		},
+		{
+			{"_msg", `def`},
+			{"a", `1`},
+		},
+		{
+			{"a", `3`},
+			{"b", `54`},
+		},
+	}, [][]Field{
+		{
+			{"x", "2.5"},
+		},
+	})
+
+	f("stats by (a) avg(b) as x", [][]Field{
+		{
+			{"_msg", `abc`},
+			{"a", `1`},
+			{"b", `3`},
+		},
+		{
+			{"_msg", `def`},
+			{"a", `1`},
+		},
+		{
+			{"a", `3`},
+			{"b", `5`},
+		},
+		{
+			{"a", `3`},
+			{"b", `7`},
+		},
+	}, [][]Field{
+		{
+			{"a", "1"},
+			{"x", "3"},
+		},
+		{
+			{"a", "3"},
+			{"x", "6"},
+		},
+	})
+
+	f("stats by (a) avg(*) as x", [][]Field{
+		{
+			{"_msg", `abc`},
+			{"a", `1`},
+			{"b", `3`},
+		},
+		{
+			{"_msg", `def`},
+			{"a", `1`},
+			{"c", "3"},
+		},
+		{
+			{"a", `3`},
+			{"b", `5`},
+		},
+		{
+			{"a", `3`},
+			{"b", `7`},
+		},
+	}, [][]Field{
+		{
+			{"a", "1"},
+			{"x", "2"},
+		},
+		{
+			{"a", "3"},
+			{"x", "4.5"},
+		},
+	})
+
+	f("stats by (a) avg(c) as x", [][]Field{
+		{
+			{"_msg", `abc`},
+			{"a", `1`},
+			{"b", `3`},
+		},
+		{
+			{"_msg", `def`},
+			{"a", `1`},
+		},
+		{
+			{"a", `3`},
+			{"c", `5`},
+		},
+		{
+			{"a", `3`},
+			{"b", `7`},
+		},
+	}, [][]Field{
+		{
+			{"a", "1"},
+			{"x", "NaN"},
+		},
+		{
+			{"a", "3"},
+			{"x", "5"},
+		},
+	})
+
+	f("stats by (a) avg(a, b, c) as x", [][]Field{
+		{
+			{"_msg", `abc`},
+			{"a", `1`},
+			{"b", `3`},
+		},
+		{
+			{"_msg", `def`},
+			{"a", `1`},
+			{"c", "3"},
+		},
+		{
+			{"a", `3`},
+			{"b", `5`},
+		},
+		{
+			{"a", `3`},
+			{"b", `7`},
+		},
+	}, [][]Field{
+		{
+			{"a", "1"},
+			{"x", "2"},
+		},
+		{
+			{"a", "3"},
+			{"x", "4.5"},
+		},
+	})
+
+	f("stats by (a, b) avg(a) as x", [][]Field{
+		{
+			{"_msg", `abc`},
+			{"a", `1`},
+			{"b", `3`},
+		},
+		{
+			{"_msg", `def`},
+			{"a", `1`},
+			{"c", "3"},
+		},
+		{
+			{"a", `3`},
+			{"b", `5`},
+		},
+	}, [][]Field{
+		{
+			{"a", "1"},
+			{"b", "3"},
+			{"x", "1"},
+		},
+		{
+			{"a", "1"},
+			{"b", ""},
+			{"x", "1"},
+		},
+		{
+			{"a", "3"},
+			{"b", "5"},
+			{"x", "3"},
+		},
+	})
+
+	f("stats by (a, b) avg(c) as x", [][]Field{
+		{
+			{"_msg", `abc`},
+			{"a", `1`},
+			{"b", `3`},
+		},
+		{
+			{"_msg", `def`},
+			{"a", `1`},
+			{"c", "3"},
+		},
+		{
+			{"a", `3`},
+			{"b", `5`},
+		},
+	}, [][]Field{
+		{
+			{"a", "1"},
+			{"b", "3"},
+			{"x", "NaN"},
+		},
+		{
+			{"a", "1"},
+			{"b", ""},
+			{"x", "3"},
+		},
+		{
+			{"a", "3"},
+			{"b", "5"},
+			{"x", "NaN"},
+		},
+	})
+}
+
+func expectParseStatsFuncFailure(t *testing.T, s string) {
+	t.Helper()
+
+	lex := newLexer(s)
+	sf, err := parseStatsFunc(lex)
+	if err == nil && lex.isEnd() {
+		t.Fatalf("expecting error when parsing [%s]; parsed result: [%s]", s, sf)
+	}
+}
+
+func expectParseStatsFuncSuccess(t *testing.T, s string) {
+	t.Helper()
+
+	lex := newLexer(s)
+	p, err := parseStatsFunc(lex)
+	if err != nil {
+		t.Fatalf("cannot parse [%s]: %s", s, err)
+	}
+	if !lex.isEnd() {
+		t.Fatalf("unexpected tail after parsing [%s]: [%s]", s, lex.s)
+	}
+
+	sResult := p.String()
+	if sResult != s {
+		t.Fatalf("unexpected string representation of stats func; got\n%s\nwant\n%s", sResult, s)
+	}
+}