Avoid calling ord(None) if at EOF

Port of projectfluent/fluent.js#265

Author: stasm

fluent/syntax/ftlstream.py

@@ -97,10 +97,11 @@ def is_identifier_start(self):
         return is_id
 
     def is_number_start(self):
-        if self.current_is('-'):
-            self.peek()
+        ch = self.peek() if self.current_is('-') else self.current()
+        if ch is None:
+            return False
 
-        cc = ord(self.current_peek())
+        cc = ord(ch)
         is_digit = cc >= 48 and cc <= 57
         self.reset_peek()
         return is_digit

tests/syntax/fixtures_structure/dash_at_eof.ftl

@@ -0,0 +1,8 @@
+### BE CAREFUL WHEN EDITING THIS FILE
+###
+### The last character in this file is the dash ("-") on line 8.
+### We want to test a literal which starts like a negative number.
+### Most editors automatically add a trailing newline at EOF.
+### If you edit this file make sure to turn this behavior off.
+
+key1 = {-

tests/syntax/fixtures_structure/dash_at_eof.json

@@ -0,0 +1,43 @@
+{
+  "type": "Resource",
+  "body": [
+    {
+      "type": "ResourceComment",
+      "content": "BE CAREFUL WHEN EDITING THIS FILE\n\nThe last character in this file is the dash (\"-\") on line 8.\nWe want to test a literal which starts like a negative number.\nMost editors automatically add a trailing newline at EOF.\nIf you edit this file make sure to turn this behavior off.",
+      "span": {
+        "type": "Span",
+        "start": 0,
+        "end": 298
+      }
+    },
+    {
+      "type": "Junk",
+      "annotations": [
+        {
+          "type": "Annotation",
+          "code": "E0004",
+          "args": [
+            "a-zA-Z"
+          ],
+          "message": "Expected a character from range: \"a-zA-Z\"",
+          "span": {
+            "type": "Span",
+            "start": 309,
+            "end": 309
+          }
+        }
+      ],
+      "content": "key1 = {-",
+      "span": {
+        "type": "Span",
+        "start": 300,
+        "end": 309
+      }
+    }
+  ],
+  "span": {
+    "type": "Span",
+    "start": 0,
+    "end": 309
+  }
+}