Tell the software's npm scope from a node in the particulars check, and compile its matchers once (issue 1838)

@novox/mesh-sdk and @novox:registry= are the software's package path, as the Go module path is; who@node
is still a node name (1838/AC2). Reading every module, a regexp compiled per name per line made the
check take 41 s; compiled once, 7.5 s.

checks/particulars/main.go

@@ -8,7 +8,7 @@
 // CamelCase boundary parts one, so a longer word holding a name is another word.
 // Three names hold a node name and are not one, so they are blanked before a line is read: the forge's host
 // (git.novox.be) and organisation path (novox/<repo>), the hardware model (asus-zephyrus-g14, ROG Zephyrus G14)
-// and the software's own name (Novox Mesh, novox-mesh).
+// and the software's own name and npm scope (Novox Mesh, novox-mesh, @novox/mesh-sdk).
 //
 //	go run . <catalogue root>
 //
@@ -33,8 +33,10 @@ var forge = regexp.MustCompile(`(?i)git\.novox\.be(?:/novox/[\w.-]+)?|(?:^|[^/\w
 
 // ownNames are the hardware model's and the software's own names, blanked before a line is read: the model
 // in any separator and case (asus-zephyrus-g14, ASUS_ZEPHYRUS_G14, ROG Zephyrus G14), the software as two
-// words or hyphened, whole (Novox Mesh, novox mesh, novox-mesh), so novox-mesh-vault stays a node name joined.
-var ownNames = regexp.MustCompile(`(?i)(?:asus[-_ ])?zephyrus[-_ ]g14|(?:^|[^\w-])novox[- ]mesh(?:$|[^\w-])`)
+// words or hyphened, whole (Novox Mesh, novox mesh, novox-mesh), so novox-mesh-vault stays a node name joined;
+// and the software's npm scope (@novox/mesh-sdk, @novox:registry=), its package path as the Go module path is,
+// where no word stands before the @, so a session's who@node (fix-1@novox) is still a node name.
+var ownNames = regexp.MustCompile(`(?i)(?:asus[-_ ])?zephyrus[-_ ]g14|(?:^|[^\w-])novox[- ]mesh(?:$|[^\w-])|(?:^|[^\w.-])@novox(?:$|[^\w-])`)
 
 func main() {
 	root := "."
@@ -173,12 +175,24 @@ func hits(line string, names []string) []string {
 	line = ownNames.ReplaceAllStringFunc(line, blank)
 	var out []string
 	for _, n := range names {
-		q := regexp.QuoteMeta(n)
-		camel := regexp.QuoteMeta(strings.ToUpper(n[:1]) + n[1:])
-		rx := regexp.MustCompile(`(?i:(?:^|[^A-Za-z0-9])` + q + `(?:$|[^A-Za-z0-9]))|[a-z0-9]` + camel + `(?:$|[^a-z])|(?:^|[^A-Za-z0-9])` + q + `[A-Z0-9]`)
-		if rx.MatchString(line) {
+		if matcher(n).MatchString(line) {
 			out = append(out, strings.ToLower(n))
 		}
 	}
 	return out
 }
+
+// matchers holds each name's matcher, compiled once: the check reads every line of every module.
+var matchers = map[string]*regexp.Regexp{}
+
+// matcher is the matcher of one name: as a word, or as a part of a CamelCase identifier.
+func matcher(n string) *regexp.Regexp {
+	if rx, ok := matchers[n]; ok {
+		return rx
+	}
+	q := regexp.QuoteMeta(n)
+	camel := regexp.QuoteMeta(strings.ToUpper(n[:1]) + n[1:])
+	rx := regexp.MustCompile(`(?i:(?:^|[^A-Za-z0-9])` + q + `(?:$|[^A-Za-z0-9]))|[a-z0-9]` + camel + `(?:$|[^a-z])|(?:^|[^A-Za-z0-9])` + q + `[A-Z0-9]`)
+	matchers[n] = rx
+	return rx
+}

checks/particulars/main_test.go

@@ -169,3 +169,32 @@ func TestANodeNameBesideTheHardwareOrTheSoftwareIsRefused(t *testing.T) {
 		}
 	}
 }
+
+// 1838/AC2: the software's npm scope (@novox/mesh-sdk, @novox:registry=) is its package path, as the Go module
+// path is; a session's who@node naming a node is still a node name.
+func TestTheSoftwaresNpmScopeIsNotANodeName(t *testing.T) {
+	for _, s := range []string{
+		"printf '%s\\n' ${shellQuote(`@novox:registry=${registry}`)}",
+		"const url = `${asked}@novox%2fmesh-sdk`;",
+		"# The @novox scope resolves from the mesh's own package registry",
+		`"dependencies": { "@novox/mesh-sdk": "^0.1.0" }`,
+	} {
+		if got := scan("f", s, names); len(got) != 0 {
+			t.Errorf("%q refused: %v", s, got)
+		}
+	}
+	for _, s := range []string{"by fix-1@novox", "jochen@novox:"} {
+		if got := scan("f", s, names); len(got) != 1 {
+			t.Errorf("%q gave %v, want one finding", s, got)
+		}
+	}
+}
+
+// 1838/AC1: reading every module, the check compiles its matchers once, not once a line: a line read costs a
+// few allocations, not a regexp compiled per name (the whole catalogue took 41 s with one per line).
+func TestALineIsReadWithoutCompilingAMatcher(t *testing.T) {
+	line := "a line of code that names nothing at all, with git.novox.be/novox/mesh-sdk in it"
+	if n := testing.AllocsPerRun(100, func() { hits(line, names) }); n > 20 {
+		t.Errorf("a line costs %.0f allocations, want at most 20", n)
+	}
+}