fix(3622): prevent panic in signature help for import.defer (#3626)

Author: a-tarasyuk

internal/checker/checker.go

@@ -8309,6 +8309,9 @@ func (c *Checker) resolveCallExpression(node *ast.Node, candidatesOutArray *[]*S
 		}
 		return c.resolveUntypedCall(node)
 	}
+	if ast.IsImportCall(node) {
+		return c.resolveUntypedCall(node)
+	}
 	var callChainFlags SignatureFlags
 	funcType := c.checkExpression(node.Expression())
 	if isCallChain(node) {

internal/fourslash/tests/manual/signatureHelpOnImportDefer_test.go

@@ -0,0 +1,20 @@
+package fourslash_test
+
+import (
+	"testing"
+
+	"github.com/microsoft/typescript-go/internal/fourslash"
+	"github.com/microsoft/typescript-go/internal/testutil"
+)
+
+func TestSignatureHelpOnImportDefer(t *testing.T) {
+	t.Parallel()
+	defer testutil.RecoverAndFail(t, "Panic on fourslash test")
+	const content = `let m = import.defer(/**/)`
+
+	f, done := fourslash.NewFourslash(t, nil /*capabilities*/, content)
+	defer done()
+
+	f.GoToMarker(t, "")
+	f.VerifyBaselineSignatureHelp(t)
+}

testdata/baselines/reference/fourslash/signatureHelp/signatureHelpOnImportDefer.baseline

@@ -0,0 +1,21 @@
+// === SignatureHelp ===
+=== /signatureHelpOnImportDefer.ts ===
+// let m = import.defer()
+//                      ^
+// | ----------------------------------------------------------------------
+// | No signaturehelp at /**/.
+// | ----------------------------------------------------------------------
+[
+  {
+    "marker": {
+      "Position": 21,
+      "LSPosition": {
+        "line": 0,
+        "character": 21
+      },
+      "Name": "",
+      "Data": {}
+    },
+    "item": null
+  }
+]