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|
package moonbitlang_test
import (
"context"
"errors"
"os"
"os/exec"
"path/filepath"
"strings"
"testing"
"time"
"github.com/gdamore/tcell/v2"
"rickub.com/turbo-editors/turbo-core/app"
"rickub.com/turbo-editors/turbo-core/buffer"
"rickub.com/turbo-editors/turbo-core/lsp"
"rickub.com/turbo-editors/turbo-core/syntax"
"rickub.com/turbo-editors/turbo-core/ui"
"rickub.com/turbo-editors/turbo-moonbit/internal/moonbitlang"
)
// --- the editor, assembled --------------------------------------------------
func TestTheEditorCallsItselfTurboMoonBit(t *testing.T) {
editor := newTestEditor(t)
if got := editor.Profile().Name; got != moonbitlang.Name {
t.Errorf("Profile().Name = %q, want %q", got, moonbitlang.Name)
}
if got := editor.Profile().ProjectDir(); got != ".turbo-moonbit" {
t.Errorf("ProjectDir() = %q, want %q", got, ".turbo-moonbit")
}
}
func TestTheEditorColoursMoonBitSourceItOpens(t *testing.T) {
// The whole path in one test: Register taught the library about MoonBit,
// the profile named the editor, and a .mbt file opened through the public
// API comes out coloured.
root := t.TempDir()
path := filepath.Join(root, "main.mbt")
writeFile(t, path, "fn main {\n println(\"hi\")\n}\n")
editor := newTestEditor(t)
editor.Open(path)
if got := editor.ActiveView().Language(); got != moonbitlang.Language {
t.Fatalf("the view colours the file as %q, want %q", got, moonbitlang.Language)
}
if spans := syntax.Highlight(moonbitlang.Language, "fn main {"); len(spans[0]) == 0 {
t.Error("the registered MoonBit scanner colours nothing")
}
}
func TestAnInterfaceFileIsMoonBitToo(t *testing.T) {
// A .mbti is generated by `moon info` and read in review. It is MoonBit
// and nothing else, so it opens coloured.
root := t.TempDir()
path := filepath.Join(root, "pkg.generated.mbti")
writeFile(t, path, "package \"example/demo\"\n\npub fn helper() -> Int\n")
editor := newTestEditor(t)
editor.Open(path)
if got := editor.ActiveView().Language(); got != moonbitlang.Language {
t.Errorf("a .mbti file is coloured as %q, want %q", got, moonbitlang.Language)
}
}
func TestTheEditorDoesNotColourPython(t *testing.T) {
// "MoonBit instead of Python" is the whole point of this editor being a
// separate one: a .py file opens as plain text here.
root := t.TempDir()
path := filepath.Join(root, "main.py")
writeFile(t, path, "def main() -> None:\n pass\n")
editor := newTestEditor(t)
editor.Open(path)
if got := editor.ActiveView().Language(); got != syntax.LanguageNone {
t.Errorf("a .py file is coloured as %q; Turbo MoonBit registers MoonBit, not Python", got)
}
}
func TestAProjectsOwnFilesAreStillColouredByTheLibrary(t *testing.T) {
// moon.pkg.json and a README are what a MoonBit project is made of besides
// its source, and turbo-core colours both without this editor doing
// anything. That the inherited languages survive registration is worth one
// test, because syntax.Register writes into package-level state.
root := t.TempDir()
editor := newTestEditor(t)
for name, want := range map[string]syntax.Language{
"README.md": syntax.LanguageMarkdown,
"README.mbt.md": syntax.LanguageMarkdown,
"ci.yml": syntax.LanguageYAML,
} {
path := filepath.Join(root, name)
writeFile(t, path, "# heading\n")
editor.Open(path)
if got := editor.ActiveView().Language(); got != want {
t.Errorf("%s is coloured as %q, want %q", name, got, want)
}
}
}
func TestTheToolchainMenuIsCalledMoonBitAndNoTwoMenusShareAHotKey(t *testing.T) {
// The bar answers the first menu whose hot key matches, so a clash makes
// one of the two unreachable from the keyboard — silently, and with every
// other test still passing. MoonBit takes M because none of the fixed menus
// does, which is exactly the sort of thing only this test notices.
editor := newTestEditor(t)
seen := map[rune]string{}
found := false
for _, menu := range editor.MenuBar().Menus() {
label, hot, _ := ui.SplitHotKey(menu.Label)
if label == "MoonBit" {
found = true
}
if hot == 0 {
t.Errorf("the %q menu has no hot key", label)
continue
}
if other, clash := seen[hot]; clash {
t.Errorf("%q and %q both answer to Alt-%c", other, label, hot)
}
seen[hot] = label
}
if !found {
t.Error("there is no MoonBit menu on the bar")
}
}
// --- driven against a real moon-lsp -----------------------------------------
// TestCompletionEndToEndWithRealMoonLSP drives the exact sequence the command
// does at start-up: open the files first, start the language server second,
// then ask for a completion.
//
// That order is the whole point, and it is the one Turbo Go got wrong once: an
// editor that announces its open documents to a server which does not exist yet
// and never mentions them again gets answers about a file the server has never
// heard of — which looks, from the outside, exactly like completion not
// working.
//
// It skips itself when the MoonBit toolchain is not installed, and under
// -short.
func TestCompletionEndToEndWithRealMoonLSP(t *testing.T) {
root, editor := startRealServer(t)
// The line on disk is blank. The text the completion is about gets *typed*
// below, so the answer can only come from what the editor told the server —
// which is the whole point of this test. A fixture already containing
// "text." would be answered from disk, and would pass whether or not the
// editor said anything at all.
path := filepath.Join(root, "main.mbt")
view := editor.ActiveView()
view.Buffer().SetCursor(buffer.Position{Line: completionLine, Col: 2})
typeText(editor, "text.")
// Typing the dot asks for a completion by itself, but a server that is
// still indexing answers nothing at all. Asking again until it answers is
// what a person does too.
if !waitForCompletion(t, editor) {
t.Fatalf("no completion list opened for %s; the status bar says %q", path, editor.StatusBar().Message())
}
// length() is a String method, so an answer holding it is an answer about
// the *type* of the name that was typed, not a list of every word in the
// file.
if !completionOffers(editor, "length") {
t.Errorf("the list does not offer String's length; it has %d entries", editor.Completion().Count())
}
}
// Several answers, not one. An earlier version of the library took the first
// location and threw the rest away, so a name used in three places sent you to
// whichever one the server happened to list first.
func TestReferencesAcrossAFileWithRealMoonLSP(t *testing.T) {
root, editor := startRealServer(t)
path := filepath.Join(root, "main.mbt")
locations := waitForLocations(t, func(ctx context.Context) ([]lsp.Location, error) {
return editor.Language().References(ctx, path, helperLine, helperColumn, helperLineText)
})
if len(locations) < 3 {
t.Errorf("helper has %d references, want at least 3 — its declaration and its two call sites: %v",
len(locations), locations)
}
}
func TestGoToDefinitionWithRealMoonLSP(t *testing.T) {
root, editor := startRealServer(t)
path := filepath.Join(root, "main.mbt")
locations := waitForLocations(t, func(ctx context.Context) ([]lsp.Location, error) {
return editor.Language().Definition(ctx, path, callLine, callColumn, callLineText)
})
if len(locations) != 1 {
t.Fatalf("the call to helper has %d definitions, want exactly 1: %v", len(locations), locations)
}
if got := locations[0].Range.Start.Line; got != helperLine {
t.Errorf("the definition of helper is on line %d, want %d", got, helperLine)
}
}
func TestTheSymbolsOfAFileWithRealMoonLSP(t *testing.T) {
root, editor := startRealServer(t)
path := filepath.Join(root, "main.mbt")
var symbols []lsp.Symbol
waitUntil(t, 30*time.Second, func() bool {
ctx, cancel := context.WithTimeout(t.Context(), 5*time.Second)
defer cancel()
found, err := editor.Language().DocumentSymbols(ctx, path)
if err != nil {
return false
}
symbols = found
return len(symbols) > 0
})
names := map[string]bool{}
for _, symbol := range symbols {
names[symbol.Name] = true
}
for _, want := range []string{"helper", "first", "second", "main"} {
if !names[want] {
t.Errorf("the file's symbols do not include %q: %v", want, names)
}
}
}
func TestTheProjectsSymbolsWithRealMoonLSP(t *testing.T) {
// moon-lsp advertises workspaceSymbolProvider, which pylsp does not — so
// Code ▸ Symbol in project and Ctrl-T really answer here.
_, editor := startRealServer(t)
var symbols []lsp.Symbol
waitUntil(t, 30*time.Second, func() bool {
ctx, cancel := context.WithTimeout(t.Context(), 5*time.Second)
defer cancel()
found, err := editor.Language().WorkspaceSymbols(ctx, "helper")
if err != nil {
return false
}
symbols = found
return len(symbols) > 0
})
if len(symbols) == 0 {
t.Error("moon-lsp answered no project-wide symbols for \"helper\"")
}
}
// Diagnostics are the one thing a language server sends without being asked,
// and the only feature whose failure looks exactly like success: an editor with
// no error to show and one that cannot find the error are the same blank
// gutter. So this opens a file that does not compile and waits for the mark.
//
// The file is on disk before the server starts, which is what a person actually
// does — the code was already broken when they opened it. The other order does
// not work, and the test below says so rather than leaving it to be discovered.
func TestDiagnosticsForAFileThatDoesNotCompileWithRealMoonLSP(t *testing.T) {
root, editor := startRealServerOn(t, brokenProject)
path := filepath.Join(root, "main.mbt")
waitUntil(t, 30*time.Second, func() bool {
editor.Tick()
return len(editor.Language().Diagnostics(path)) > 0
})
problems := editor.Language().Diagnostics(path)
if len(problems) == 0 {
t.Fatalf("no diagnostic ever arrived for %s; the status bar says %q", path, editor.StatusBar().Message())
}
if _, ok := editor.Language().FirstError(path); !ok {
t.Errorf("the diagnostics hold no error, only %v", problems)
}
}
// A .mbt file that did not exist when moon-lsp first analysed the package is
// diagnosed from its first save. It was not, until turbo-core v1.0.2: the
// server works out which files a package holds from the directory, and a
// document being open and a file existing are two different facts to it — a
// file saved for the first time got no diagnostics however loudly the document
// had been announced, until the editor also sent
// workspace/didChangeWatchedFiles. The test that pinned that limit went red on
// macOS on 2026-09-19, where moon-lsp evidently notices new files by itself;
// on Linux it does not, and the notification is what makes this pass.
//
// The scenario is the one a person lives: `turbo-moonbit late.mbt` on a file
// that is not there yet, type, and let the save happen — here automatic
// saving, the one exported way to write a buffer without a dialog.
func TestAFileCreatedInTheEditorIsDiagnosedFromItsFirstSaveWithRealMoonLSP(t *testing.T) {
root, editor := startRealServer(t)
late := filepath.Join(root, "late.mbt")
editor.Open(late) // not on disk: an empty buffer with that name
editor.Tick()
editor.SetAutosave(true, 10*time.Millisecond)
typeText(editor, "///|\nfn oops() -> Int {\n undefined_name()\n}\n")
waitUntil(t, 30*time.Second, func() bool {
editor.Tick()
return len(editor.Language().Diagnostics(late)) > 0
})
if _, err := os.Stat(late); err != nil {
t.Fatalf("the file was never written, so this proves nothing about the server: %v", err)
}
if !editor.Language().Knows(late) {
t.Error("the editor never told the server about the new file")
}
if len(editor.Language().Diagnostics(late)) == 0 {
t.Errorf("no diagnostic arrived for a file created after the server started; the status bar says %q", editor.StatusBar().Message())
}
}
// moon-lsp advertises neither typeDefinitionProvider nor implementationProvider,
// so two of the nine questions turbo-core asks come back empty. That is
// documented in how-to/enable-completion.md, and this test is what keeps the
// documentation honest: if a future moon-lsp answers either of them, this fails
// and the page gets revisited.
func TestMoonLSPAnswersNeitherTypeDefinitionsNorImplementations(t *testing.T) {
root, editor := startRealServer(t)
path := filepath.Join(root, "main.mbt")
ctx, cancel := context.WithTimeout(t.Context(), 15*time.Second)
defer cancel()
if found, err := editor.Language().TypeDefinition(ctx, path, helperLine, helperColumn, helperLineText); err == nil && len(found) > 0 {
t.Errorf("moon-lsp now answers type definitions (%v); how-to/enable-completion.md says it does not", found)
}
if found, err := editor.Language().Implementation(ctx, path, helperLine, helperColumn, helperLineText); err == nil && len(found) > 0 {
t.Errorf("moon-lsp now answers implementations (%v); how-to/enable-completion.md says it does not", found)
}
}
// --- the fixtures and the waiting -------------------------------------------
// realProject is the file every language-server test works against. Line
// numbers are counted from zero and are named by the constants below, so
// inserting a line here moves them and the constants have to move too.
//
// 0 ///|
// 1 fn helper() -> Int {
// 2 1
// 3 }
// 4
// 5 ///|
// 6 fn first() -> Int {
// 7 helper()
// 8 }
// 9
// 10 ///|
// 11 fn second() -> Int {
// 12 helper() + 1
// 13 }
// 14
// 15 ///|
// 16 fn main {
// 17 let text = "hi"
// 18 ← two spaces, and where the completion is typed
// 19 println(first() + second() + text.length())
// 20 }
//
// It compiles with no errors and no warnings under `moon check`, which matters:
// a fixture the toolchain complains about would make the diagnostics test pass
// for the wrong reason.
const realProject = "///|\n" +
"fn helper() -> Int {\n" +
" 1\n" +
"}\n" +
"\n" +
"///|\n" +
"fn first() -> Int {\n" +
" helper()\n" +
"}\n" +
"\n" +
"///|\n" +
"fn second() -> Int {\n" +
" helper() + 1\n" +
"}\n" +
"\n" +
"///|\n" +
"fn main {\n" +
" let text = \"hi\"\n" +
" \n" +
" println(first() + second() + text.length())\n" +
"}\n"
// brokenProject is a project whose one file does not compile. It exists as a
// second fixture rather than as a file added to the first, because a package
// holding an error is a package whose *other* answers are worth nothing: the
// completion test would then be measuring a broken build.
const brokenProject = "///|\n" +
"fn main {\n" +
" undefined_name()\n" +
"}\n"
// Where the fixture's interesting lines are, counted from zero.
const (
completionLine = 18
helperLine = 1
helperColumn = 3
helperLineText = "fn helper() -> Int {"
callLine = 7
callColumn = 2
callLineText = " helper()"
)
// startRealServer writes a project, opens its file, starts moon-lsp and waits
// for it, in the order the command does. It skips the test when the MoonBit
// toolchain is missing.
func startRealServer(t *testing.T) (root string, editor *app.App) {
t.Helper()
return startRealServerOn(t, realProject)
}
// startRealServerOn is startRealServer over a chosen main.mbt.
func startRealServerOn(t *testing.T, source string) (root string, editor *app.App) {
t.Helper()
if testing.Short() {
t.Skip("-short: not starting a language server")
}
server, err := lsp.FindServer(moonbitlang.Profile().Server)
if errors.Is(err, lsp.ErrServerNotFound) {
t.Skipf("%s is not installed; %s", moonbitlang.ServerCommand, moonbitlang.InstallHint)
}
// Finding it is not the same as being able to run it: a shim left behind by
// a tool manager whose environment has since been removed is on PATH and
// fails only when started.
if !serverRuns(server) {
t.Skipf("%s at %s cannot run; %s", moonbitlang.ServerCommand, server, moonbitlang.InstallHint)
}
root = t.TempDir()
writeFile(t, filepath.Join(root, "moon.mod"), "name = \"example/demo\"\nversion = \"0.1.0\"\n")
writeFile(t, filepath.Join(root, "moon.pkg"), "pkgtype(kind: \"executable\")\n")
writeFile(t, filepath.Join(root, "main.mbt"), source)
editor = newTestEditor(t)
// 1. Open the file, exactly as main does — before there is any server.
editor.Open(filepath.Join(root, "main.mbt"))
// 2. Start the language server, exactly as main does — afterwards.
ctx, cancel := context.WithCancel(t.Context())
t.Cleanup(cancel)
editor.StartLanguageServer(ctx, root)
t.Cleanup(func() { editor.Language().Stop(context.Background()) })
waitUntilReady(t, editor)
// 3. Let the event loop notice the server is ready, as Run does on every
// turn. This is what announces the file that was already open.
editor.Tick()
return root, editor
}
// newTestEditor returns Turbo MoonBit drawing on a simulated terminal, set up
// the way the command sets it up.
func newTestEditor(t *testing.T) *app.App {
t.Helper()
moonbitlang.Register()
screen := tcell.NewSimulationScreen("UTF-8")
if err := screen.Init(); err != nil {
t.Fatalf("initialising the simulation screen: %v", err)
}
t.Cleanup(screen.Fini)
screen.SetSize(80, 24)
// Never read the themes or snippets of whoever is running the tests.
p := moonbitlang.Profile()
t.Setenv(p.ThemeDirEnvVar(), t.TempDir())
t.Setenv(p.SnippetDirEnvVar(), t.TempDir())
editor := app.New(screen, "turbo-classic", p)
editor.Render()
return editor
}
// typeText sends a run of printable characters through the whole routing chain.
func typeText(editor *app.App, text string) {
for _, r := range text {
// A newline is the Enter key, not a rune: typed as a rune it is
// dropped, and a fixture meant to span four lines lands on one —
// where `///|` turns the whole of it into a doc comment.
if r == '\n' {
editor.Handle(tcell.NewEventKey(tcell.KeyEnter, 0, tcell.ModNone))
continue
}
editor.Handle(tcell.NewEventKey(tcell.KeyRune, r, tcell.ModNone))
}
}
// completionOffers reports whether the open popup holds an entry starting with
// a label.
func completionOffers(editor *app.App, label string) bool {
for _, item := range editor.Completion().Matches() {
if strings.HasPrefix(item.Label, label) {
return true
}
}
return false
}
// waitUntilReady blocks until the language server has finished starting.
func waitUntilReady(t *testing.T, editor *app.App) {
t.Helper()
deadline := time.After(lsp.InitializeTimeout)
for !editor.Language().Ready() {
select {
case <-deadline:
t.Fatalf("the language server never became ready: %s", editor.Language().Status())
case <-time.After(10 * time.Millisecond):
}
}
}
// waitUntil polls a condition until it holds or the time runs out, and fails
// the test if it never does.
func waitUntil(t *testing.T, within time.Duration, done func() bool) {
t.Helper()
deadline := time.Now().Add(within)
for time.Now().Before(deadline) {
if done() {
return
}
time.Sleep(200 * time.Millisecond)
}
t.Errorf("the server never answered within %s", within)
}
// waitForLocations asks a location question until it is answered, because a
// server that is still indexing answers an empty list rather than an error.
func waitForLocations(t *testing.T, ask func(context.Context) ([]lsp.Location, error)) []lsp.Location {
t.Helper()
var found []lsp.Location
waitUntil(t, 30*time.Second, func() bool {
ctx, cancel := context.WithTimeout(t.Context(), 5*time.Second)
defer cancel()
locations, err := ask(ctx)
if err != nil {
return false
}
found = locations
return len(found) > 0
})
return found
}
// waitForCompletion asks for a completion until one arrives, or gives up.
//
// A server loads the workspace after it has finished initialising, and answers
// an empty list until that is done. There is no notification this client reads
// that says when — so it asks again, which is what the editor's user would do.
func waitForCompletion(t *testing.T, editor *app.App) bool {
t.Helper()
deadline := time.Now().Add(60 * time.Second)
for time.Now().Before(deadline) {
if editor.Completion().Visible() {
return true
}
editor.RequestCompletion()
if editor.Completion().Visible() {
return true
}
time.Sleep(500 * time.Millisecond)
}
return false
}
// serverRuns reports whether the language server at path actually starts.
func serverRuns(path string) bool {
return exec.Command(path, "--version").Run() == nil
}
// writeFile creates a file, making its directory first.
func writeFile(t *testing.T, path, content string) {
t.Helper()
if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
t.Fatalf("creating %s: %v", filepath.Dir(path), err)
}
if err := os.WriteFile(path, []byte(content), 0o644); err != nil {
t.Fatalf("writing %s: %v", path, err)
}
}
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