warn on deprecated features (#2726)

- `function.arguments`
- `function.callers`

fixes #2719

1 files changed, 32 insertions, 0 deletions

diff --git a/test/compress/issue-2719.js b/test/compress/issue-2719.js
new file mode 100644
index 00000000..93e51d7c
--- /dev/null
+++ b/test/compress/issue-2719.js
@@ -0,0 +1,32 @@
+warn: {
+    options = {
+        evaluate: true,
+        inline: true,
+        passes: 2,
+        properties: true,
+        reduce_funcs: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        function f() {
+            return g();
+        }
+        function g() {
+            return g["call" + "er"].arguments;
+        }
+        // 3
+        console.log(f(1, 2, 3).length);
+    }
+    expect: {
+        // TypeError: Cannot read property 'arguments' of null
+        console.log(function g() {
+            return g.caller.arguments;
+        }().length);
+    }
+    expect_warnings: [
+        "WARN: Function.protoype.caller not supported [test/compress/issue-2719.js:17,19]",
+        "WARN: Function.protoype.arguments not supported [test/compress/issue-2719.js:17,19]",
+    ]
+}