10 files changed, 28 insertions, 15 deletions

diff --git a/js/compiler.ts b/js/compiler.ts
index c872afa14..bac328937 100644
--- a/js/compiler.ts
+++ b/js/compiler.ts
@@ -152,6 +152,7 @@ export class DenoCompiler
   // arguments
   private readonly _options: Readonly<ts.CompilerOptions> = {
     allowJs: true,
+    checkJs: true,
     module: ts.ModuleKind.AMD,
     outDir: "$deno$",
     // TODO https://github.com/denoland/deno/issues/23
diff --git a/tests/error_008_checkjs.js b/tests/error_008_checkjs.js
new file mode 100644
index 000000000..08d4873c7
--- /dev/null
+++ b/tests/error_008_checkjs.js
@@ -0,0 +1,6 @@
+// console.log intentionally misspelled to trigger a type error
+consol.log("hello world!");
+
+// the following error should be ignored and not output to the console
+// @ts-ignore
+const foo = new Foo();
diff --git a/tests/error_008_checkjs.js.out b/tests/error_008_checkjs.js.out
new file mode 100644
index 000000000..9220efaf1
--- /dev/null
+++ b/tests/error_008_checkjs.js.out
@@ -0,0 +1,10 @@
+[WILDCARD]/tests/error_008_checkjs.jsILDCARD] - error TS2552: Cannot find name 'consol'. Did you mean 'console'?
+
+ILDCARD] consol.log("hello world!");
+[WILDCARD]~~~~~~
+
+  $asset$/lib.deno_runtime.d.tsILDCARD]
+[WILDCARD]declare const console: console_.Console;
+[WILDCARD]~~~~~~~
+[WILDCARD]'console' is declared here.
+
diff --git a/tests/subdir/mt_application_ecmascript.j2.js b/tests/subdir/mt_application_ecmascript.j2.js
index ec30e0595..e67d2a017 100644
--- a/tests/subdir/mt_application_ecmascript.j2.js
+++ b/tests/subdir/mt_application_ecmascript.j2.js
@@ -1,3 +1 @@
-define(["exports"], function(exports) {
-  exports.loaded = true;
-});
+export const loaded = true;
diff --git a/tests/subdir/mt_application_x_javascript.j4.js b/tests/subdir/mt_application_x_javascript.j4.js
index ec30e0595..e67d2a017 100644
--- a/tests/subdir/mt_application_x_javascript.j4.js
+++ b/tests/subdir/mt_application_x_javascript.j4.js
@@ -1,3 +1 @@
-define(["exports"], function(exports) {
-  exports.loaded = true;
-});
+export const loaded = true;
diff --git a/tests/subdir/mt_javascript.js b/tests/subdir/mt_javascript.js
index ec30e0595..e67d2a017 100644
--- a/tests/subdir/mt_javascript.js
+++ b/tests/subdir/mt_javascript.js
@@ -1,3 +1 @@
-define(["exports"], function(exports) {
-  exports.loaded = true;
-});
+export const loaded = true;
diff --git a/tests/subdir/mt_text_ecmascript.j3.js b/tests/subdir/mt_text_ecmascript.j3.js
index ec30e0595..e67d2a017 100644
--- a/tests/subdir/mt_text_ecmascript.j3.js
+++ b/tests/subdir/mt_text_ecmascript.j3.js
@@ -1,3 +1 @@
-define(["exports"], function(exports) {
-  exports.loaded = true;
-});
+export const loaded = true;
diff --git a/tests/subdir/mt_text_javascript.j1.js b/tests/subdir/mt_text_javascript.j1.js
index ec30e0595..e67d2a017 100644
--- a/tests/subdir/mt_text_javascript.j1.js
+++ b/tests/subdir/mt_text_javascript.j1.js
@@ -1,3 +1 @@
-define(["exports"], function(exports) {
-  exports.loaded = true;
-});
+export const loaded = true;
diff --git a/tsconfig.json b/tsconfig.json
index e6bf1688b..806143644 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,7 +1,9 @@
 {
   "compilerOptions": {
+    "allowJs": true,
     "allowUnreachableCode": false,
     "baseUrl": ".",
+    "checkJs": true,
     "module": "esnext",
     "moduleResolution": "node",
     "noImplicitReturns": true,
diff --git a/website/app.js b/website/app.js
index 5185c936a..375c6a54b 100644
--- a/website/app.js
+++ b/website/app.js
@@ -148,10 +148,12 @@ function generate(
     };
   }
 
+  // @ts-ignore
   c3.generate({
     bindto: id,
     size: {
       height: 300,
+      // @ts-ignore
       width: window.chartWidth || 375 // TODO: do not use global variable
     },
     data: {
@@ -200,6 +202,7 @@ export async function drawChartsFromBenchmarkData(dataUrl) {
   const sha1ShortList = sha1List.map(sha1 => sha1.substring(0, 6));
 
   const viewCommitOnClick = _sha1List => d => {
+    // @ts-ignore
     window.open(
       `https://github.com/denoland/deno/commit/${_sha1List[d["index"]]}`
     );
@@ -229,6 +232,7 @@ export async function drawChartsFromBenchmarkData(dataUrl) {
  */
 export async function drawChartsFromTravisData() {
   const viewPullRequestOnClick = _prNumberList => d => {
+    // @ts-ignore
     window.open(
       `https://github.com/denoland/deno/pull/${_prNumberList[d["index"]]}`
     );