Write into a file the machine shares instead of over it, and reload a service that re-reads its configuration instead of restarting it (hq ADR 0102)

internal/declaration/into_test.go

@@ -0,0 +1,35 @@
+package declaration
+
+import (
+	"strings"
+	"testing"
+)
+
+// Defends novox/hq ADR 0102: a file written into carries only a JSON object of its keys, in a
+// format the host speaks, and a service may name what it is reloaded on.
+
+func TestAFileWrittenIntoIsRefusedUnlessItIsAnObjectOfKeys(t *testing.T) {
+	for name, c := range map[string]struct{ resource, refusal string }{
+		"another format":   {`{"id":"f","type":"file","path":"/etc/x","into":"toml","content":"a = 1"}`, `into "toml"`},
+		"not an object":    {`{"id":"f","type":"file","path":"/etc/x","into":"json","content":"[1,2]"}`, "JSON object"},
+		"with create-once": {`{"id":"f","type":"file","path":"/etc/x","into":"json","content":"{}","create-once":true}`, "create-once"},
+	} {
+		_, err := Parse([]byte(`{"declaration":1,"resources":[` + c.resource + `]}`))
+		if err == nil || !strings.Contains(err.Error(), c.refusal) {
+			t.Errorf("%s: want a refusal naming %q, got %v", name, c.refusal, err)
+		}
+	}
+	d, err := Parse([]byte(`{"declaration":1,"resources":[
+	  {"id":"f","type":"file","path":"/etc/x","into":"json","content":"{\"k\":1}"},
+	  {"id":"s","type":"service","unit":"docker.service","state":"running","reload-on":["f"]}
+	]}`))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if f := d.Resources[0].(*File); f.Into != IntoJSON {
+		t.Errorf("into was read as %q", f.Into)
+	}
+	if s := d.Resources[1].(*Service); len(s.ReloadOn) != 1 || s.ReloadOn[0] != "f" {
+		t.Errorf("reload-on was read as %v", s.ReloadOn)
+	}
+}