fix: remove import cycles

contribs/nocycles/main.go

@@ -0,0 +1,146 @@
+package main
+
+import (
+	"fmt"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/gnolang/gno/gnovm"
+	"github.com/gnolang/gno/gnovm/pkg/gnoenv"
+	"github.com/gnolang/gno/gnovm/pkg/gnolang"
+	"github.com/gnolang/gno/gnovm/pkg/gnomod"
+	"github.com/gnolang/gno/gnovm/pkg/packages"
+)
+
+func main() {
+	// set to true to dump the final pkg list
+	verbose := true
+
+	// find stdlibs
+	libs := []string{}
+	gnoRoot := gnoenv.RootDir()
+	stdlibsDir := filepath.Join(gnoRoot, "gnovm", "stdlibs")
+	fs.WalkDir(os.DirFS(stdlibsDir), ".", func(path string, d fs.DirEntry, err error) error {
+		if !d.IsDir() {
+			return nil
+		}
+		if path == "." {
+			return nil
+		}
+		libs = append(libs, path)
+		return nil
+	})
+
+	// read stdlibs
+	pl := gnomod.PkgList{}
+	for _, lib := range libs {
+		memPkg := gnolang.MustReadMemPackage(filepath.Join(stdlibsDir, lib), lib)
+		pkg, xpkg, err := splitMemPackage(memPkg)
+		if err != nil {
+			panic(fmt.Errorf("split %q: %w", lib, err))
+		}
+		{
+			imports, err := packages.Imports(pkg)
+			if err != nil {
+				panic(fmt.Errorf("read %q: %w", lib, err))
+			}
+			pl = append(pl, gnomod.Pkg{
+				Dir:     "",
+				Name:    lib,
+				Imports: imports,
+			})
+		}
+		if !xpkg.IsEmpty() {
+			imports, err := packages.Imports(xpkg)
+			if err != nil {
+				panic(fmt.Errorf("read %q: %w", lib, err))
+			}
+			pl = append(pl, gnomod.Pkg{
+				Dir:     "",
+				Name:    "_test_" + lib,
+				Imports: imports,
+			})
+		}
+	}
+
+	// load all examples
+	examples, err := gnomod.ListPkgs(filepath.Join(gnoRoot, "examples"))
+	if err != nil {
+		panic(fmt.Errorf("load examples: %w", err))
+	}
+	for _, example := range examples {
+		if example.Draft {
+			continue
+		}
+		pkgPath := example.Name
+		memPkg := gnolang.MustReadMemPackage(example.Dir, example.Name)
+		pkg, xpkg, err := splitMemPackage(memPkg)
+		if err != nil {
+			panic(fmt.Errorf("split %q: %w", pkgPath, err))
+		}
+		{
+			imports, err := packages.Imports(pkg)
+			if err != nil {
+				panic(fmt.Errorf("read %q: %w", pkgPath, err))
+			}
+			pl = append(pl, gnomod.Pkg{
+				Dir:     example.Dir,
+				Name:    pkgPath,
+				Imports: imports,
+			})
+		}
+		if !xpkg.IsEmpty() {
+			imports, err := packages.Imports(xpkg)
+			if err != nil {
+				panic(fmt.Errorf("read %q: %w", pkgPath, err))
+			}
+			pl = append(pl, gnomod.Pkg{
+				Dir:     example.Dir,
+				Name:    "_test_" + pkgPath,
+				Imports: imports,
+			})
+		}
+	}
+
+	// detect import cycles
+	if _, err := pl.Sort(); err != nil {
+		panic(err)
+	}
+
+	if verbose {
+		for _, p := range pl {
+			fmt.Println(p.Name)
+		}
+	}
+}
+
+func splitMemPackage(pkg *gnovm.MemPackage) (*gnovm.MemPackage, *gnovm.MemPackage, error) {
+	corePkg := gnovm.MemPackage{
+		Name: pkg.Name,
+		Path: pkg.Path,
+	}
+	xtestPkg := gnovm.MemPackage{
+		Name: pkg.Name + "_test",
+		Path: pkg.Path,
+	}
+
+	for _, file := range pkg.Files {
+		if !strings.HasSuffix(file.Name, "_test.gno") {
+			corePkg.Files = append(corePkg.Files, file)
+			continue
+		}
+		pkgName, err := packages.FilePackageName(file.Name, file.Body)
+		if err != nil {
+			return nil, nil, fmt.Errorf("get package name in file %q: %w", file.Name, err)
+		}
+		if !strings.HasSuffix(pkgName, "_test") {
+			corePkg.Files = append(corePkg.Files, file)
+			continue
+		}
+		xtestPkg.Files = append(xtestPkg.Files, file)
+	}
+
+	return &corePkg, &xtestPkg, nil
+}

examples/gno.land/p/moul/md/md_test.gno

@@ -1,4 +1,4 @@
-package md
+package md_test
 
 import (
 	"testing"

examples/gno.land/r/gnoland/faucet/faucet_test.gno

@@ -1,4 +1,4 @@
-package faucet
+package faucet_test
 
 import (
 	"std"

gnovm/pkg/gnomod/pkg.go

@@ -39,39 +39,45 @@ type (
 // sortPkgs sorts the given packages by their dependencies.
 func (pl PkgList) Sort() (SortedPkgList, error) {
 	visited := make(map[string]bool)
-	onStack := make(map[string]bool)
+	stack := []string{}
 	sortedPkgs := make([]Pkg, 0, len(pl))
 
 	// Visit all packages
 	for _, p := range pl {
-		if err := visitPackage(p, pl, visited, onStack, &sortedPkgs); err != nil {
+		if err := visitPackage(p, pl, visited, stack, &sortedPkgs); err != nil {
 			return nil, err
 		}
 	}
 
 	return sortedPkgs, nil
 }
 
+var injectedTestingLib = []string{"encoding/json", "fmt", "os", "internal/os_test"}
+
 // visitNode visits a package's and its dependencies dependencies and adds them to the sorted list.
-func visitPackage(pkg Pkg, pkgs []Pkg, visited, onStack map[string]bool, sortedPkgs *[]Pkg) error {
-	if onStack[pkg.Name] {
-		return fmt.Errorf("cycle detected: %s", pkg.Name)
+func visitPackage(pkg Pkg, pkgs []Pkg, visited map[string]bool, stack []string, sortedPkgs *[]Pkg) error {
+	if slices.Contains(stack, pkg.Name) {
+		return fmt.Errorf("cycle detected: %s -> %s", strings.Join(stack, " -> "), pkg.Name)
 	}
 	if visited[pkg.Name] {
 		return nil
 	}
 
 	visited[pkg.Name] = true
-	onStack[pkg.Name] = true
+	stack = append(stack, pkg.Name)
 
 	// Visit package's dependencies
 	for _, imp := range pkg.Imports {
+		if slices.Contains(injectedTestingLib, imp) {
+			continue
+		}
+
 		found := false
 		for _, p := range pkgs {
 			if p.Name != imp {
 				continue
 			}
-			if err := visitPackage(p, pkgs, visited, onStack, sortedPkgs); err != nil {
+			if err := visitPackage(p, pkgs, visited, stack, sortedPkgs); err != nil {
 				return err
 			}
 			found = true
@@ -82,7 +88,6 @@ func visitPackage(pkg Pkg, pkgs []Pkg, visited, onStack map[string]bool, sortedP
 		}
 	}
 
-	onStack[pkg.Name] = false
 	*sortedPkgs = append(*sortedPkgs, pkg)
 	return nil
 }

gnovm/pkg/packages/imports.go

@@ -70,3 +70,12 @@ func FileImports(filename string, src string) ([]*FileImport, *token.FileSet, er
 	}
 	return res, fs, nil
 }
+
+func FilePackageName(filename string, src string) (string, error) {
+	fs := token.NewFileSet()
+	f, err := parser.ParseFile(fs, filename, src, parser.PackageClauseOnly)
+	if err != nil {
+		return "", err
+	}
+	return f.Name.Name, nil
+}

gnovm/stdlibs/crypto/ed25519/ed25519_test.gno

@@ -1,4 +1,4 @@
-package ed25519
+package ed25519_test
 
 import (
 	"crypto/ed25519"

gnovm/stdlibs/crypto/sha256/sha256_test.gno

@@ -1,4 +1,4 @@
-package sha256
+package sha256_test
 
 import (
 	"crypto/sha256"

gnovm/stdlibs/encoding/binary/binary_test.gno

@@ -1,4 +1,4 @@
-package binary
+package binary_test
 
 import (
 	"bytes"

gnovm/stdlibs/hash/marshal_test.gno

@@ -6,7 +6,7 @@
 // BinaryMarshaler, BinaryUnmarshaler,
 // and lock in the current representations.
 
-package hash
+package hash_test
 
 import (
 	"bytes"

gnovm/stdlibs/io/export_test.gno

@@ -0,0 +1,10 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package io
+
+// exported for test
+var ErrInvalidWrite = errInvalidWrite
+var ErrWhence = errWhence
+var ErrOffset = errOffset