fix: [JS/TS/Tests] Remove mocha to resolve package vulnerabilities

.vscode/launch.json

@@ -151,8 +151,8 @@
     //     "type": "node",
     //     "request": "launch",
     //     "name": "Run bench-compiler JS tests",
-    //     "program": "${workspaceFolder}/node_modules/mocha/bin/_mocha",
-    //     "args": ["out-tests"],
+    //     "program": "out-tests/Main.js",
+    //     "args": ["--test"],
     //     "cwd": "${workspaceRoot}/src/fable-standalone/test/bench-compiler"
     // },
     // {

package.json

@@ -4,29 +4,27 @@
   "name": "fable-compiler",
   "scripts": {
     "tsc": "tsc",
-    "mocha": "mocha",
     "rollup": "rollup",
     "terser": "terser",
     "build": "dotnet fsi build_old.fsx",
     "publish": "dotnet fsi build_old.fsx publish",
     "test": "dotnet run --project src/Fable.Build/Fable.Build.fsproj -- test",
-    "tests": "mocha temp/tests/JavaScript/Main --reporter dot -t 10000",
+    "tests": "node --test-reporter spec --test-timeout 20000 --test temp/tests/JavaScript/Main/Main.js",
+    "tests-ts": "tsc -p temp/tests/TypeScript --outDir temp/tests/TypeScriptCompiled",
+    "posttests-ts": "node --test-reporter spec --test-timeout 20000 --test temp/tests/TypeScriptCompiled/temp/tests/TypeScript/Main.js",
     "build-compiler-js": "dotnet fable src/fable-compiler-js/src/fable-compiler-js.fsproj -o build/fable-compiler-js/out",
     "postbuild-compiler-js": "rollup build/fable-compiler-js/out/app.js --file src/fable-compiler-js/dist/app.js --format umd --name Fable",
     "minify-compiler-js": "terser src/fable-compiler-js/dist/app.js -o src/fable-compiler-js/dist/app.min.js --mangle --compress",
-    "test-js": "node src/fable-compiler-js/dist/app.js tests/Main/Fable.Tests.fsproj build/tests-js",
-    "posttest-js": "mocha build/tests-js --reporter dot -t 10000",
-    "test-ts": "tsc -p build/tests/TypeScript --outDir build/tests/TypeScriptCompiled",
-    "posttest-ts": "mocha build/tests/TypeScriptCompiled/build/tests/TypeScript -reporter dot -t 10000"
+    "tests-compiler-js": "node src/fable-compiler-js/dist/app.js tests/Main/Fable.Tests.fsproj temp/tests-compiler-js",
+    "posttests-compiler-js": "node --test-reporter spec --test-timeout 20000 --test temp/tests-compiler-js/Main.js"
   },
   "dependencies": {
-    "@types/node": "^25.6.0",
+    "@types/node": "^25.8.0",
     "concurrently": "^9.2.1",
     "ghreleases": "^3.0.2",
-    "mocha": "^11.7.5",
     "nodemon": "^3.1.14",
-    "rollup": "^4.60.3",
-    "terser": "^5.46.2",
+    "rollup": "^4.60.4",
+    "terser": "^5.47.1",
     "typescript": "^5.9.3"
   },
   "devDependencies": {

src/Fable.Build/Test/Integration.fs

@@ -29,9 +29,11 @@ let private testProjectConfig (projectDirName: string) (configuration: string op
         |> CmdLine.appendPrefix "--exclude" "Fable.Core"
         |> CmdLine.appendPrefixIfSome "--configuration" configuration
 
+    let testArgs = "--test-reporter spec --test-timeout 20000 --test Main.js"
+
     Command.Fable(fableArgs)
 
-    Command.Run("npx", "npx mocha . --reporter dot -t 10000", workingDirectory = destinationDir)
+    Command.Run("node", testArgs, workingDirectory = destinationDir)
 
 let handle (args: string list) =
     BuildFableLibraryJavaScript().Run()

src/Fable.Build/Test/JavaScript.fs

@@ -52,13 +52,12 @@ let private testAdaptive (isWatch: bool) =
 
     let destinationDir = Path.Resolve("temp", "tests", "JavaScript", folderName)
 
-    let mochaCommand =
+    let testCommand =
         CmdLine.empty
-        |> CmdLine.appendRaw "npx"
-        |> CmdLine.appendRaw "mocha"
-        |> CmdLine.appendRaw destinationDir
-        |> CmdLine.appendPrefix "--reporter" "dot"
-        |> CmdLine.appendPrefix "-t" "10000"
+        |> CmdLine.appendRaw "node"
+        |> CmdLine.appendPrefix "--test-reporter" "spec"
+        |> CmdLine.appendPrefix "--test-timeout" "20000"
+        |> CmdLine.appendPrefix "--test" (destinationDir </> "Main.js")
         |> CmdLine.toString
 
     Directory.clean destinationDir
@@ -77,9 +76,9 @@ let private testAdaptive (isWatch: bool) =
                     CmdLine.empty
                     |> CmdLine.appendRaw "--watch"
                     |> CmdLine.appendRaw "--runWatch"
-                    |> CmdLine.appendRaw mochaCommand
+                    |> CmdLine.appendRaw testCommand
                 else
-                    CmdLine.empty |> CmdLine.appendRaw "--run" |> CmdLine.appendRaw mochaCommand
+                    CmdLine.empty |> CmdLine.appendRaw "--run" |> CmdLine.appendRaw testCommand
             ]
 
     if isWatch then
@@ -93,13 +92,12 @@ let private handleMainTests (isWatch: bool) (noDotnet: bool) =
 
     let destinationDir = Path.Resolve("temp", "tests", "JavaScript", folderName)
 
-    let mochaCommand =
+    let testCommand =
         CmdLine.empty
-        |> CmdLine.appendRaw "npx"
-        |> CmdLine.appendRaw "mocha"
-        |> CmdLine.appendRaw destinationDir
-        |> CmdLine.appendPrefix "--reporter" "dot"
-        |> CmdLine.appendPrefix "-t" "10000"
+        |> CmdLine.appendRaw "node"
+        |> CmdLine.appendPrefix "--test-reporter" "spec"
+        |> CmdLine.appendPrefix "--test-timeout" "20000"
+        |> CmdLine.appendPrefix "--test" (destinationDir </> "Main.js")
         |> CmdLine.toString
 
     Directory.clean destinationDir
@@ -118,9 +116,9 @@ let private handleMainTests (isWatch: bool) (noDotnet: bool) =
                     CmdLine.empty
                     |> CmdLine.appendRaw "--watch"
                     |> CmdLine.appendRaw "--runWatch"
-                    |> CmdLine.appendRaw mochaCommand
+                    |> CmdLine.appendRaw testCommand
                 else
-                    CmdLine.empty |> CmdLine.appendRaw "--run" |> CmdLine.appendRaw mochaCommand
+                    CmdLine.empty |> CmdLine.appendRaw "--run" |> CmdLine.appendRaw testCommand
             ]
 
     if isWatch then

src/Fable.Build/Test/Standalone.fs

@@ -11,7 +11,7 @@ open SimpleExec
 let private mainTestProject =
     Path.Resolve("tests", "Js", "Main", "Fable.Tests.fsproj")
 
-let private mochaCommand = "npx mocha . --reporter dot -t 10000"
+let private testArgs = "--test-reporter spec --test-timeout 20000 --test Main.js"
 
 let handleStandaloneFast () =
     let fableCompilerJsDir = Path.Resolve("src", "fable-compiler-js", "src")
@@ -41,7 +41,7 @@ let handleStandaloneFast () =
         workingDirectory = fableCompilerJsDir
     )
 
-    Command.Run("npx", mochaCommand, workingDirectory = standaloneBuildDest)
+    Command.Run("node", testArgs, workingDirectory = standaloneBuildDest)
 
 let handle (args: string list) =
     BuildFableLibraryJavaScript().Run()

src/Fable.Build/Test/TypeScript.fs

@@ -24,7 +24,9 @@ let handle (args: string list) =
     Shell.copyFile fableDest (projectDir </> "tsconfig.json")
 
     let tscArgs = $"tsc --outDir {tscDest}"
-    let mochaArgs = "mocha temp/tests/TypeScript --reporter dot -t 10000"
+
+    let testArgs =
+        "--test-reporter spec --test-timeout 20000 --test temp/tests/TypeScript/Main.js"
 
     let fableArgs =
         CmdLine.concat
@@ -53,8 +55,8 @@ let handle (args: string list) =
         // Avoid polluting the logs when a lot of files change at once
         |> CmdLine.appendPrefix "--delay" "1s"
         |> CmdLine.appendRaw "--exec"
-        |> CmdLine.appendRaw "\""
-        |> CmdLine.appendRaw mochaArgs
+        |> CmdLine.appendRaw "\"node"
+        |> CmdLine.appendRaw testArgs
         |> CmdLine.appendRaw "\""
         |> CmdLine.toString
 
@@ -80,4 +82,4 @@ let handle (args: string list) =
 
         Command.Run("npx", tscArgs, workingDirectory = fableDest)
 
-        Command.Run("npx", mochaArgs, workingDirectory = tscDest)
+        Command.Run("node", testArgs, workingDirectory = tscDest)

src/fable-standalone/test/bench-compiler/package.json

@@ -70,8 +70,8 @@
     "build-tests-ts": "npm run build-tests-js -- --fableLib ./out-lib-ts --lang TypeScript",
     "build-tests-opt": "npm run build-tests-js -- --optimize",
     "build-tests-node": "npm run fable-node -- ../../../../tests/Js/Main/Fable.Tests.fsproj --outDir ./out-tests --fableLib ./out-lib-js --sourceMaps",
-    "postbuild-tests-js": "npm run mocha -- out-tests --colors --reporter dot -t 10000",
-    "postbuild-tests-node": "npm run mocha -- out-tests --colors --reporter dot -t 10000",
+    "postbuild-tests-js": "node --test-reporter spec --test-timeout 20000 --test out-tests/Main.js",
+    "postbuild-tests-node": "node --test-reporter spec --test-timeout 20000 --test out-tests/Main.js",
 
     "build-tests-rust": "npm run fable -- ../../../../tests/Rust/Fable.Tests.Rust.fsproj --outDir ./out-tests-rust --fableLib ./out-lib-rust --lang Rust",
     "build-tests-dart": "npm run fable -- ../../../../tests/Dart/src/Fable.Tests.Dart.fsproj --outDir ./out-tests-dart --fableLib ./out-lib-dart --lang Dart",
@@ -84,7 +84,6 @@
 
     "tsc": "node ../../../../node_modules/typescript/bin/tsc",
     "babel": "node ../../../../node_modules/@babel/cli/bin/babel",
-    "mocha": "node ../../../../node_modules/mocha/bin/mocha",
     "rollup": "node ../../../../node_modules/rollup/dist/bin/rollup",
     "terser": "node ../../../../node_modules/terser/bin/terser",
     "webpack": "node ../../../../node_modules/webpack-cli/bin/cli.js",

tests/Integration/ProjectConfigs/ConsoleApp/Fable.Tests.ConsoleApp.fsproj

@@ -7,7 +7,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <Compile Include="Program.fs" />
+    <Compile Include="Main.fs" />
   </ItemGroup>
 
   <ItemGroup>

tests/Integration/ProjectConfigs/ConsoleApp/Program.fs → tests/Integration/ProjectConfigs/ConsoleApp/Main.fs

@@ -4,8 +4,9 @@ open Fable.Core
 open Fable.Core.JsInterop
 open Fable.Core.Testing
 
-let [<Global>] describe (name: string) (f: unit->unit) : unit = jsNative
-let [<Global>] it (msg: string) (f: unit->unit) : unit = jsNative
+let inline describe (name: string) (f: unit->unit) : unit = import "describe" "node:test"
+let inline it (msg: string) (f: unit->unit) : unit = import "it" "node:test"
+
 let equals expected actual = Assert.AreEqual(actual, expected)
 
 describe "ConsoleApp" (fun () ->

tests/Integration/ProjectConfigs/CustomConfiguration/Main.fs

@@ -4,8 +4,9 @@ open Fable.Core
 open Fable.Core.JsInterop
 open Fable.Core.Testing
 
-let [<Global>] describe (name: string) (f: unit->unit) : unit = jsNative
-let [<Global>] it (msg: string) (f: unit->unit) : unit = jsNative
+let inline describe (name: string) (f: unit->unit) : unit = import "describe" "node:test"
+let inline it (msg: string) (f: unit->unit) : unit = import "it" "node:test"
+
 let equals expected actual = Assert.AreEqual(actual, expected)
 
 describe "CustomConfiguration" (fun () ->

tests/Integration/ProjectConfigs/DebugWithExtraDefines/Main.fs

@@ -4,8 +4,9 @@ open Fable.Core
 open Fable.Core.JsInterop
 open Fable.Core.Testing
 
-let [<Global>] describe (name: string) (f: unit->unit) : unit = jsNative
-let [<Global>] it (msg: string) (f: unit->unit) : unit = jsNative
+let inline describe (name: string) (f: unit->unit) : unit = import "describe" "node:test"
+let inline it (msg: string) (f: unit->unit) : unit = import "it" "node:test"
+
 let equals expected actual = Assert.AreEqual(actual, expected)
 
 describe "DebugWithExtraDefines" (fun () ->

tests/Integration/ProjectConfigs/ReleaseNoExtraDefines/Main.fs

@@ -4,8 +4,9 @@ open Fable.Core
 open Fable.Core.JsInterop
 open Fable.Core.Testing
 
-let [<Global>] describe (name: string) (f: unit->unit) : unit = jsNative
-let [<Global>] it (msg: string) (f: unit->unit) : unit = jsNative
+let inline describe (name: string) (f: unit->unit) : unit = import "describe" "node:test"
+let inline it (msg: string) (f: unit->unit) : unit = import "it" "node:test"
+
 let equals expected actual = Assert.AreEqual(actual, expected)
 
 describe "ReleaseNoExtraDefines" (fun () ->

tests/Js/Adaptive/Main.fs

@@ -11,8 +11,8 @@ let allTests =
 open Fable.Core
 open Fable.Core.JsInterop
 
-let [<Global>] describe (name: string) (f: unit->unit) : unit = jsNative
-let [<Global>] it (msg: string) (f: unit->unit) : unit = jsNative
+let inline describe (name: string) (f: unit->unit) : unit = import "describe" "node:test"
+let inline it (msg: string) (f: unit->unit) : unit = import "it" "node:test"
 
 
 let rec flattenTest (test: Util.Testing.TestKind) : unit =

tests/Js/Main/DateTimeTests.fs

@@ -1127,18 +1127,6 @@ let tests =
 
         t |> equal (TimeSpan(0, 13, 23, 30, 1))
 
-    testCaseAsync "Timer with AutoReset = true works" <| fun () ->
-        async {
-            let res = ref 0
-            let t = new Timers.Timer(50.)
-            t.Elapsed.Add(fun ev -> res := !res + 5)
-            t.Start()
-            do! Async.Sleep 125
-            t.Stop()
-            do! Async.Sleep 50
-            equal 10 !res
-        }
-
     testCaseAsync "Timer with AutoReset = false works" <| fun () ->
         async {
             let res = ref 0
@@ -1151,6 +1139,18 @@ let tests =
             equal 5 !res
         }
 
+    testCaseAsync "Timer with AutoReset = true works" <| fun () ->
+        async {
+            let res = ref 0
+            let t = new Timers.Timer(50.)
+            t.Elapsed.Add(fun ev -> res := !res + 5)
+            t.Start()
+            do! Async.Sleep 125
+            t.Stop()
+            do! Async.Sleep 50
+            equal 10 !res
+        }
+
     testCaseAsync "Timer.Elapsed.Subscribe works" <| fun () ->
         async {
             let res = ref 0

tests/Js/Main/InlineIfLambdaTests.fs

@@ -78,7 +78,7 @@ let tests =
             let result =
                 applyPairTwice
                     (fun a b ->
-                        printfn "Adding %d and %d" a b
+                        // printfn "Adding %d and %d" a b
                         a + b
                     )
                     10

tests/Js/Main/Main.fs

@@ -67,8 +67,8 @@ open Fable.Core.JsInterop
 // but not available in node.js runtime
 importSideEffects "./js/polyfill.js"
 
-let [<Global>] describe (name: string) (f: unit->unit) : unit = jsNative
-let [<Global>] it (msg: string) (f: unit->unit) : unit = jsNative
+let inline describe (name: string) (f: unit->unit) : unit = import "describe" "node:test"
+let inline it (msg: string) (f: unit->unit) : unit = import "it" "node:test"
 
 
 let rec flattenTest (test: Util.Testing.TestKind) : unit =

tests/Python/TestInlineIfLambda.fs

@@ -72,7 +72,7 @@ let ``test InlineIfLambda with two parameters works`` () =
     let result =
         applyPairTwice
             (fun a b ->
-                printfn "Adding %d and %d" a b
+                // printfn "Adding %d and %d" a b
                 a + b
             )
             10

tests/TypeScript/Main.fs

@@ -65,14 +65,8 @@ open Fable.Core.JsInterop
 // but not available in node.js runtime
 importSideEffects "../Js/Main/js/polyfill.js"
 
-let [<Global>] describe (name: string) (f: unit->unit) : unit = jsNative
-let [<Global>] it (msg: string) (f: unit->unit) : unit = jsNative
-
-// TODO: Emit declarations automatically when there are global variables
-emitJsStatement () """
-declare var it: any;
-declare var describe: any;
-"""
+let inline describe (name: string) (f: unit->unit) : unit = import "describe" "node:test"
+let inline it (msg: string) (f: unit->unit) : unit = import "it" "node:test"
 
 let rec flattenTest (test: Util.Testing.TestKind) : unit =
     match test with