👍 show constraint error warning

autoload/denops/_internal/server/proc.vim

@@ -1,4 +1,5 @@
 const s:SCRIPT = denops#_internal#path#script(['@denops-private', 'cli.ts'])
+const s:LAST_ERROR_LINES = 20
 
 let s:job = v:null
 let s:stopped_on_purpose = 0
@@ -59,13 +60,13 @@ function! s:start(options) abort
   if g:denops#deno_dir isnot# v:null
     let l:env['DENO_DIR'] = g:denops#deno_dir
   endif
-  let l:store = {'prepared': 0}
+  let l:store = {'prepared': 0, 'stderr': []}
   let s:stopped_on_purpose = 0
   let s:job = denops#_internal#job#start(l:args, {
         \ 'env': l:env,
         \ 'on_stdout': { _job, data, _event -> s:on_stdout(l:store, data) },
-        \ 'on_stderr': { _job, data, _event -> s:on_stderr(data) },
-        \ 'on_exit': { _job, status, _event -> s:on_exit(a:options, status) },
+        \ 'on_stderr': { _job, data, _event -> s:on_stderr(l:store, data) },
+        \ 'on_exit': { _job, status, _event -> s:on_exit(l:store, a:options, status) },
         \})
   call denops#_internal#echo#debug(printf('Server started: %s', l:args))
   call denops#_internal#event#emit('DenopsSystemProcessStarted')
@@ -84,18 +85,36 @@ function! s:on_stdout(store, data) abort
   call denops#_internal#event#emit(printf('DenopsSystemProcessListen:%s', l:addr))
 endfunction
 
-function! s:on_stderr(data) abort
+function! s:on_stderr(store, data) abort
   echohl ErrorMsg
   for l:line in split(a:data, '\n')
     echomsg printf('[denops] %s', substitute(l:line, '\t', '    ', 'g'))
   endfor
   echohl None
+  if a:store.stderr->add(a:data)->len() > s:LAST_ERROR_LINES
+    eval a:store.stderr->remove(0, -(s:LAST_ERROR_LINES + 1))
+  endif
 endfunction
 
-function! s:on_exit(options, status) abort
+function! s:on_exit(store, options, status) abort
   let s:job = v:null
   call denops#_internal#echo#debug(printf('Server stopped: %s', a:status))
   call denops#_internal#event#emit(printf('DenopsSystemProcessStopped:%s', a:status))
+  const l:last_error = a:store.stderr->join("\n")
+  if l:last_error =~# 'Could not find constraint\|Could not find version of'
+    " Show a warning message when Deno module cache issue is detected
+    " https://github.com/vim-denops/denops.vim/issues/358
+    call denops#_internal#echo#warn(repeat('*', 80))
+    call denops#_internal#echo#warn('Deno module cache issue is detected.')
+    call denops#_internal#echo#warn(
+          \ "Execute 'call denops#cache#update(#{reload: v:true})' and restart Vim/Neovim."
+          \ )
+    call denops#_internal#echo#warn(
+          \ 'See https://github.com/vim-denops/denops.vim/issues/358 for more detail.'
+          \ )
+    call denops#_internal#echo#warn(repeat('*', 80))
+    return
+  endif
   if s:job isnot# v:null || !a:options.restart_on_exit || s:stopped_on_purpose || s:exiting
     return
   endif

deno.jsonc

@@ -10,7 +10,8 @@
     "apply:supported-versions": "deno run --allow-read --allow-write .scripts/apply_supported_versions.ts"
   },
   "exclude": [
-    ".coverage/"
+    ".coverage/",
+    "tests/denops/testdata/no_check/"
   ],
   // NOTE: Import maps should only be used from test modules.
   "imports": {

tests/denops/runtime/functions/server_test.ts

@@ -3,7 +3,9 @@ import {
   assertEquals,
   assertFalse,
   assertMatch,
+  assertNotMatch,
   assertRejects,
+  assertStringIncludes,
 } from "jsr:@std/assert@^1.0.1";
 import { delay } from "jsr:@std/async@^0.224.0/delay";
 import { AsyncDisposableStack } from "jsr:@nick/dispose@^1.1.0/async-disposable-stack";
@@ -489,6 +491,56 @@ testHost({
         );
       });
     });
+
+    await t.step(
+      "if the server is stopped with a constraint error",
+      async (t) => {
+        await using stack = new AsyncDisposableStack();
+        stack.defer(async () => {
+          await host.call("denops#server#stop");
+          await wait(
+            () => host.call("eval", "denops#server#status() ==# 'stopped'"),
+          );
+        });
+
+        outputs = [];
+        await host.call("execute", [
+          "silent! unlet g:__test_denops_process_stopped_fired",
+          `let g:denops#server#deno_args = ['${
+            resolve("no_check/cli_error_on_issue_401.ts")
+          }']`,
+          "let g:denops#server#restart_delay = 1000",
+          "let g:denops#server#restart_interval = 10000",
+          "let g:denops#server#restart_threshold = 1",
+          "call denops#server#start()",
+        ], "");
+
+        await t.step("fires DenopsProcessStopped", async () => {
+          await wait(() =>
+            host.call("exists", "g:__test_denops_process_stopped_fired")
+          );
+        });
+
+        await t.step("changes status to 'stopped' asynchronously", async () => {
+          assertEquals(await host.call("denops#server#status"), "stopped");
+        });
+
+        await t.step("outputs warning message", async () => {
+          await delay(MESSAGE_DELAY);
+          assertStringIncludes(
+            outputs.join(""),
+            "Execute 'call denops#cache#update(#{reload: v:true})' and restart Vim/Neovim.",
+          );
+        });
+
+        await t.step("does not restart the server", () => {
+          assertNotMatch(
+            outputs.join(""),
+            /Server stopped.*Restarting/,
+          );
+        });
+      },
+    );
   },
 });
 
@@ -1275,3 +1327,8 @@ testHost({
     });
   },
 });
+
+/** Resolve testdata script URL. */
+function resolve(path: string): string {
+  return new URL(`../../testdata/${path}`, import.meta.url).href;
+}

tests/denops/testdata/no_check/cli_error_on_issue_401.ts

@@ -0,0 +1 @@
+import * as _ from "jsr:@std/[email protected]";