mesh-catalog/modules/mesh-build-go/buildstep/seatgen/layout_test.go

package seatgen

import (
	"encoding/json"
	"go/parser"
	"go/token"
	re "regexp"
	"strings"
	"testing"

	"git.novox.be/novox/mesh-sdk/go/seatdef"
)

// TestEachSeatDefinedWholeIsAGoModuleOfItsOwn is ADR 0625's generator check (§1, §2, §3): the seat set is one package in
// the root Go module, each seat defined whole is a Go module of its own holding its package alone, the parts it
// includes are written into it, and no generated Go file imports anything outside the standard library.
func TestEachSeatDefinedWholeIsAGoModuleOfItsOwn(t *testing.T) {
	m, err := Load("testdata/contracts", "example.org/contracts/go", "@example/contracts")
	if err != nil {
		t.Fatal(err)
	}
	files, err := Generate(m)
	if err != nil {
		t.Fatal(err)
	}
	mods := map[string]string{}
	for p, b := range files {
		if strings.HasPrefix(p, "go/") && strings.HasSuffix(p, "go.mod") {
			mods[strings.TrimSuffix(p, "go.mod")] = strings.SplitN(string(b), "\n", 2)[0]
		}
	}
	want := map[string]string{
		"go/":                 "module example.org/contracts/go",
		"go/seats/aregistry/": "module example.org/contracts/go/seats/aregistry",
		"go/seats/bregistry/": "module example.org/contracts/go/seats/bregistry",
	}
	for dir, line := range want {
		if mods[dir] != line {
			t.Errorf("%sgo.mod says %q, want %q", dir, mods[dir], line)
		}
	}
	// Every seat the definitions mark whole has its own module, whatever the seat set says of it (ADR 0627: the seat
	// set marks ten whole, and none is without its package).
	for name, d := range m.Seats {
		if d.Grain == seatdef.Whole && mods["go/seats/"+pkgName(name)+"/"] == "" {
			t.Errorf("the seat %s is defined whole and has no Go module of its own", name)
		}
	}
	if len(mods) != len(want) {
		t.Errorf("Go modules %v, want %v", mods, want)
	}
	for p, b := range files {
		if !strings.HasPrefix(p, "go/") || !strings.HasSuffix(p, ".go") {
			continue
		}
		dir := p[:strings.LastIndex(p, "/")+1]
		if dir != "go/seats/" && mods[dir] == "" {
			t.Errorf("%s is in no seat's own Go module, nor the seat set's package", p)
		}
		f, err := parser.ParseFile(token.NewFileSet(), p, b, parser.ImportsOnly)
		if err != nil {
			t.Fatal(err)
		}
		for _, im := range f.Imports {
			if path := strings.Trim(im.Path.Value, `"`); strings.Contains(strings.SplitN(path, "/", 2)[0], ".") {
				t.Errorf("%s imports %s: a generated package imports nothing outside the standard library", p, path)
			}
		}
	}
	for _, seat := range []string{"aregistry", "bregistry"} {
		src := string(files["go/seats/"+seat+"/contract.go"])
		if !strings.Contains(src, "type Ref struct") || !strings.Contains(src, "type PublishedEvent") {
			t.Errorf("%s does not hold the part's types whole", seat)
		}
		// A string's enum is a constant per value, so a caller names the definition's value (A3t: the removal reason).
		if !re.MustCompile(`RefReasonRetention\s+= "retention"`).MatchString(src) || !re.MustCompile(`RefReasonTagGone\s+= "tag-gone"`).MatchString(src) {
			t.Errorf("%s does not name the part's enum values:\n%s", seat, src)
		}
	}
	if !strings.Contains(string(files["go/seats/seats.go"]), "OneStore") {
		t.Error("the seat set does not name the seat at the seat list's grain")
	}

	// The npm side (ADR 0625 §1): the indexer counts an npm package a lock resolves, so each seat defined whole is an
	// npm package of its own (`<package>-<seat>` at ts/seats/<seat without hyphens>), holding its parts' types whole and
	// importing nothing outside itself; the seat set's package (ts/) holds the seat list alone.
	pkgs := map[string]string{}
	for p, b := range files {
		if strings.HasPrefix(p, "ts/") && strings.HasSuffix(p, "package.json") {
			var pj struct {
				Name string `json:"name"`
			}
			if err := json.Unmarshal(b, &pj); err != nil {
				t.Fatalf("%s: %v", p, err)
			}
			pkgs[strings.TrimSuffix(p, "package.json")] = pj.Name
		}
	}
	wantPkgs := map[string]string{
		"ts/":                 "@example/contracts",
		"ts/seats/aregistry/": "@example/contracts-a-registry",
		"ts/seats/bregistry/": "@example/contracts-b-registry",
	}
	if len(pkgs) != len(wantPkgs) {
		t.Errorf("npm packages %v, want %v", pkgs, wantPkgs)
	}
	for dir, name := range wantPkgs {
		if pkgs[dir] != name {
			t.Errorf("%spackage.json names %q, want %q", dir, pkgs[dir], name)
		}
	}
	for p, b := range files {
		if !strings.HasPrefix(p, "ts/") || !strings.HasSuffix(p, ".ts") {
			continue
		}
		dir := ""
		for d := range pkgs {
			if strings.HasPrefix(p, d) && len(d) > len(dir) {
				dir = d
			}
		}
		if dir == "" || !strings.HasPrefix(p, dir+"src/") {
			t.Errorf("%s is in no npm package's src", p)
		}
		for _, line := range strings.Split(string(b), "\n") {
			i := strings.Index(line, ` from "`)
			if l := strings.TrimSpace(line); i >= 0 && (strings.HasPrefix(l, "import") || strings.HasPrefix(l, "export")) {
				from := strings.Trim(line[i+len(` from `):], `";`)
				if !strings.HasPrefix(from, "./") {
					t.Errorf("%s imports %s: a generated npm package imports only its own files", p, from)
				}
			}
		}
	}
	for _, seat := range []string{"aregistry", "bregistry"} {
		if !strings.Contains(string(files["ts/seats/"+seat+"/src/index.ts"]), "export type PublishedEvent = registry.PublishedEvent") ||
			!strings.Contains(string(files["ts/seats/"+seat+"/src/parts/registry.ts"]), "export type PublishedEvent") {
			t.Errorf("the npm package of %s does not hold the part's types whole", seat)
		}
	}
	if ix := string(files["ts/src/index.ts"]); strings.Contains(ix, "Registry") || !strings.Contains(ix, "seats") {
		t.Errorf("the seat set's npm package exports a seat's contract or not the seat list:\n%s", ix)
	}
}