Warn about single-quoted translated strings

gettext only recognizes double quoted strings

blueprintcompiler/language/values.py

@@ -58,6 +58,19 @@ class Translated(AstNode):
                 f"Cannot convert translated string to {expected_type.full_name}"
             )
 
+    @validate("context")
+    def context_double_quoted(self):
+        if self.translate_context is None:
+            return
+
+        if not str(self.group.tokens["context"]).startswith('"'):
+            raise CompileWarning("gettext may not recognize single-quoted strings")
+
+    @validate("string")
+    def string_double_quoted(self):
+        if not str(self.group.tokens["string"]).startswith('"'):
+            raise CompileWarning("gettext may not recognize single-quoted strings")
+
     @docs()
     def ref_docs(self):
         return get_docs_section("Syntax Translated")

docs/translations.rst

@@ -24,6 +24,8 @@ If you're using Meson's `i18n module <https://mesonbuild.com/i18n-module.html#i1
 
    i18n.gettext('package name', preset: 'glib')
 
+You must use double quotes for the translated strings in order for gettext to recognize them. Newer versions of blueprint will warn you if you use single quotes.
+
 Contexts
 --------
 

tests/sample_errors/single_quoted_translated.blp

@@ -0,0 +1,5 @@
+using Gtk 4.0;
+
+Label {
+  label: _('Hello, World!');
+}

tests/sample_errors/single_quoted_translated.err

@@ -0,0 +1 @@
+4,12,15,gettext may not recognize single-quoted strings