cmd/mesh-controller/status.go

@@ -46,15 +46,21 @@ func statusCommand(ctx context.Context, args []string) error {
 		return err
 	}
 	defer open.Close()
+	return statusFor(ctx, open, *asJSON)
+}
 
+// statusFor asks and answers, against stores somebody else opened.
+//
+// Split from the command so what it prints can be read by a test. The sentence it prints when nothing
+// is wrong has been acted on and been misleading (novox/hq 04-ISSUES/145, 125), which makes its exact
+// words the thing worth holding still.
+func statusFor(ctx context.Context, open *stores, asJSON bool) error {
 	asked, err := theThreeQuestions(ctx, open)
 	if err != nil {
 		return err
 	}
-	wrong, nodes, quiet := asked.wrong, asked.nodes, asked.quiet
-	behind, sources := asked.behind, asked.sources
 
-	if *asJSON {
+	if asJSON {
 		body, err := statusAsJSON(asked)
 		if err != nil {
 			return err
@@ -62,6 +68,18 @@ func statusCommand(ctx context.Context, args []string) error {
 		fmt.Println(string(body))
 		return nil
 	}
+	return printStatus(asked)
+}
+
+// printStatus is the words, separated from the questions.
+//
+// **Its exact sentences have been acted on and been misleading twice** — a held module reading as a
+// machine doing what it was told (novox/hq 04-ISSUES/125), and "all doing what they were told" being
+// true of a mesh in which no module could reach another (04-ISSUES/145). So they are written where a
+// test can read them without a store, a bus or a machine.
+func printStatus(asked answers) error {
+	wrong, nodes, quiet := asked.wrong, asked.nodes, asked.quiet
+	behind, sources := asked.behind, asked.sources
 
 	if len(asked.refused) > 0 {
 		// First, above everything else. A machine that cannot be worked out is not running an old
@@ -235,6 +253,18 @@ func statusCommand(ctx context.Context, args []string) error {
 		// and getting here means every question was asked and answered.
 		fmt.Printf("%d machine(s), all doing what they were told, all heard from, running what "+
 			"the mesh would send them, and every module current with its source\n", len(nodes))
+		// **And what that sentence does not cover**, because for eleven hours it was true of a mesh
+		// in which no module could reach another (novox/hq 04-ISSUES/145). Every question above is
+		// about the relationship between the mesh and a machine — applied what it was sent, matches
+		// what would be sent, built from what the source has. None of them asks whether a module can
+		// reach what it requires, and the mesh composes every one of those grants itself.
+		//
+		// Said here rather than left to be inferred. A reader who acts on the line above is acting on
+		// "the machines are as the mesh described them", and the distance between that and "it works"
+		// is where the eleven hours went.
+		fmt.Printf("\n  That is the mesh and the machines agreeing. Nothing here dials a provision:\n" +
+			"  no grant the mesh composed has been tested, so a module unable to reach what it\n" +
+			"  requires would not appear above (04-ISSUES/145)\n")
 	}
 	return nil
 }

cmd/mesh-controller/well_scope_test.go

@@ -0,0 +1,75 @@
+package main
+
+import (
+	"bytes"
+	"io"
+	"os"
+	"strings"
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/inventory"
+)
+
+// "4 machine(s), all doing what they were told, all heard from, running what the mesh would send
+// them, and every module current with its source" was true for eleven hours of a mesh in which no
+// module could reach another (novox/hq 04-ISSUES/145). Every question it answers is about the mesh
+// and a machine agreeing; none of them dials anything.
+
+// printed captures what a function writes to stdout.
+func printed(t *testing.T, f func() error) string {
+	t.Helper()
+	old := os.Stdout
+	r, w, err := os.Pipe()
+	if err != nil {
+		t.Fatal(err)
+	}
+	os.Stdout = w
+	runErr := f()
+	_ = w.Close()
+	os.Stdout = old
+	var buf bytes.Buffer
+	if _, err := io.Copy(&buf, r); err != nil {
+		t.Fatal(err)
+	}
+	if runErr != nil {
+		t.Fatal(runErr)
+	}
+	return buf.String()
+}
+
+func TestTheAllWellSentenceSaysWhatItDoesNotCover(t *testing.T) {
+	// A mesh with nothing to say. The sentence below was true of a mesh in which no module could
+	// reach another, for eleven hours.
+	got := printed(t, func() error {
+		return printStatus(answers{nodes: []inventory.Node{{Name: "anchor"}, {Name: "laptop"}}})
+	})
+	if !strings.Contains(got, "all doing what they were told") {
+		t.Fatalf("a mesh with nothing to say did not print the all-well sentence:\n%s", got)
+	}
+	// And now says what it is not a claim about.
+	for _, want := range []string{"Nothing here dials a provision", "04-ISSUES/145"} {
+		if !strings.Contains(got, want) {
+			t.Fatalf("the all-well sentence does not say %q:\n%s", want, got)
+		}
+	}
+}
+
+func TestAMeshWithSomethingToSayDoesNotPrintTheScopeLine(t *testing.T) {
+	// The scope belongs to the all-well sentence. A mesh with something wrong has specific things to
+	// read, and appending a caveat to those is noise.
+	got := printed(t, func() error {
+		return printStatus(answers{
+			nodes:   []inventory.Node{{Name: "anchor"}},
+			untaken: map[string]map[string]int{"anchor": {"route-proxy": 3}},
+		})
+	})
+	if strings.Contains(got, "Nothing here dials a provision") {
+		t.Fatalf("a mesh with a held module printed the all-well scope line:\n%s", got)
+	}
+	if strings.Contains(got, "all doing what they were told") {
+		t.Fatalf("a mesh with a held module printed the all-well sentence:\n%s", got)
+	}
+	if !strings.Contains(got, "route-proxy") {
+		t.Fatalf("the held module is not named:\n%s", got)
+	}
+}