issue 975: a test that fails on a ticker and on a timer that names no bounded step it retries

2026-10-17 13:25:33 +02:00
parent b5225d3a2f
commit 0809a1f982
1 changed files with 85 additions and 0 deletions
@@ -0,0 +1,85 @@
+package main
+
+import (
+	"os"
+	"path/filepath"
+	"regexp"
+	"strconv"
+	"strings"
+	"testing"
+)
+
+// **A timer in this module names the bounded step it retries** (novox/hq ADR 0406 "How it is checked", issue 975): the
+// module acts on events, so a clock that fires on its own — a ticker, time.Tick — is a poll, and a one-shot timer
+// (time.AfterFunc, time.NewTimer) is allowed only for a bounded step, said in a comment on the line above:
+// `// retries: <step>`. This reads the module's Go source, not its tests.
+
+var (
+	pollingClock = regexp.MustCompile(`\btime\.(NewTicker|Tick)\(`)
+	oneShot      = regexp.MustCompile(`\btime\.(AfterFunc|NewTimer)\(`)
+	retriesLine  = regexp.MustCompile(`^\s*//\s*retries:\s*\S`)
+)
+
+// timerFaults are the lines of a source file that make a clock of their own without naming the step it retries.
+func timerFaults(name, src string) []string {
+	var faults []string
+	lines := strings.Split(src, "\n")
+	for i, line := range lines {
+		code, _, _ := strings.Cut(line, "//")
+		switch {
+		case pollingClock.MatchString(code):
+			faults = append(faults, name+":"+strconv.Itoa(i+1)+": a ticker polls; act on an event, or name a bounded step's one-shot timer: "+strings.TrimSpace(line))
+		case oneShot.MatchString(code) && (i == 0 || !retriesLine.MatchString(lines[i-1])):
+			faults = append(faults, name+":"+strconv.Itoa(i+1)+": a timer with no `// retries: <step>` comment on the line above: "+strings.TrimSpace(line))
+		}
+	}
+	return faults
+}
+
+func TestNoTimerInTheModuleFiresWithoutNamingTheBoundedStepItRetries(t *testing.T) {
+	files, err := filepath.Glob("*.go")
+	if err != nil || len(files) == 0 {
+		t.Fatalf("no source read: %v", err)
+	}
+	timers := 0
+	for _, f := range files {
+		if strings.HasSuffix(f, "_test.go") {
+			continue
+		}
+		raw, err := os.ReadFile(f)
+		if err != nil {
+			t.Fatal(err)
+		}
+		for _, fault := range timerFaults(f, string(raw)) {
+			t.Error(fault)
+		}
+		timers += len(oneShot.FindAllString(string(raw), -1))
+	}
+	if timers == 0 {
+		t.Fatal("the test found no timer at all: it is not reading the source it should")
+	}
+}
+
+// The checker itself: the tick this module had before it acted on events, and a timer that names nothing, fail; a
+// named one passes.
+func TestTheTimerCheckFailsOnATickerAndOnAnUnnamedTimer(t *testing.T) {
+	was := "\tgo func() {\n\t\ttick := time.NewTicker(10 * time.Second)\n\t\tdefer tick.Stop()\n\t}()\n"
+	if got := timerFaults("main.go", was); len(got) != 1 || !strings.Contains(got[0], "main.go:2") {
+		t.Fatalf("the old tick was not found: %v", got)
+	}
+	if got := timerFaults("x.go", "for range time.Tick(time.Second) {}\n"); len(got) != 1 {
+		t.Fatalf("time.Tick was not found: %v", got)
+	}
+	if got := timerFaults("x.go", "\ttime.AfterFunc(d, f)\n"); len(got) != 1 {
+		t.Fatalf("an unnamed timer was not found: %v", got)
+	}
+	if got := timerFaults("x.go", "\t// retries:\n\tt := time.NewTimer(d)\n"); len(got) != 1 {
+		t.Fatalf("a comment that names no step passed: %v", got)
+	}
+	if got := timerFaults("x.go", "\t// retries: the refused merge, after a minute\n\ttime.AfterFunc(d, f)\n"); len(got) != 0 {
+		t.Fatalf("a named timer failed: %v", got)
+	}
+	if got := timerFaults("x.go", "\t// time.NewTicker was here\n"); len(got) != 0 {
+		t.Fatalf("a comment about a ticker failed: %v", got)
+	}
+}