refactor override transpilation

render_static/tests/js_tests.py

@@ -3370,7 +3370,7 @@ def tearDown(self):
 
 {% override "constructor" %}
 constructor (value, name, label, alt, str, str0) {
-{{ default_impl }}
+    {{ default_impl }}
     this.constructor_context = {
         'enum': {% autoescape off %}"{{enum}}"{% endautoescape %},
         'class_name': "{{class_name}}",
@@ -3408,7 +3408,7 @@ def tearDown(self):
         'to_string': {% if to_string %}true{% else %}false{% endif %},
         'str_prop': "{{ str_prop }}"
     };
-{{ default_impl }}
+    {{ default_impl }}
 }
 {% endoverride %}
 
@@ -3424,7 +3424,7 @@ def tearDown(self):
         'to_string': {% if to_string %}true{% else %}false{% endif %},
         'str_prop': "{{ str_prop }}"
     };
-{{ default_impl }}
+    {{ default_impl }}
 }
 {% endoverride %}
 

render_static/transpilers/__init__.py

@@ -27,6 +27,7 @@
 from django.apps import apps
 from django.apps.config import AppConfig
 from django.utils.module_loading import import_module, import_string
+from django.utils.safestring import SafeString
 
 if TYPE_CHECKING:
     from render_static.templatetags.render_static import (
@@ -156,21 +157,6 @@ def get_line(self, line: Optional[str]) -> str:
         """
         return f'{self.prefix_}{self.indent_ * self.level_}{line}{self.nl_}'
 
-    def get_lines(self, lines: Generator[Optional[str], None, None]) -> str:
-        """
-        Returns a string of lines from a generator with the indentation and 
-        newlines added. This is meant to be used in place during overrides,
-        so the first newline has no indents. So it will have the line prefix
-        of {{ default_impl }}.
-        """
-        lines_str = ''
-        for idx, line in enumerate(lines):
-            if idx == 0:
-                lines_str += f'{line}{self.nl_}'
-            else:
-                lines_str += self.get_line(line)
-        return lines_str
-
     def write_line(self, line: Optional[str]) -> None:
         """
         Writes a line to the rendered code file, respecting
@@ -241,7 +227,12 @@ def parents(self):
             for parent in self.parents_
             if parent is not self.target
         ]
-
+
+    @property
+    def context(self):
+        """A local template render context passed to overrides"""
+        return {}  # pragma: no cover
+
     def __init__(
         self,
         to_javascript: Union[str, Callable] = to_javascript_,
@@ -258,6 +249,37 @@ def __init__(
         self.parents_ = []
         assert callable(self.to_javascript), 'To_javascript is not callable!'
 
+    def transpile_override(
+            self,
+            override: str,
+            default_impl: Union[str, Generator[Optional[str], None, None]]
+    ) -> Generator[str, None, None]:
+        """
+        Returns a string of lines from a generator with the indentation and 
+        newlines added. This is meant to be used in place during overrides,
+        so the first newline has no indents. So it will have the line prefix
+        of {{ default_impl }}.
+
+        :param override: The name of the override to transpile
+        :param default_impl: The default implementation to use if the override
+            is not present. May be a single line string or a generator of
+            lines.
+        """
+        d_impl = default_impl
+        if isinstance(default_impl, Generator):
+            d_impl = ''
+            for idx, line in enumerate(default_impl):
+                if idx == 0:
+                    d_impl += f'{line}{self.nl_}'
+                else:
+                    d_impl += self.get_line(line)
+            d_impl.rstrip(self.nl_)
+
+        yield from self.overrides_.pop(override).transpile({
+            **self.context,
+            'default_impl': SafeString(d_impl)
+        })
+
     @abstractmethod
     def include_target(self, target:  TranspilerTarget):
         """

render_static/transpilers/enums_to_js.py

@@ -18,7 +18,6 @@
 )
 
 from django.db.models import IntegerChoices, TextChoices
-from django.utils.safestring import SafeString
 from render_static.transpilers import Transpiler, TranspilerTarget
 
 try:
@@ -488,10 +487,7 @@ def visit(
             yield from self.to_string(enum)
             yield ''
         if 'get' in self.overrides_:
-            yield from self.overrides_.pop('get').transpile({
-                **self.context,
-                'default_impl': self.get_lines(self.getter_impl())
-            })
+            yield from self.transpile_override('get', self.getter_impl())
         else:
             yield from self.getter()
         yield ''
@@ -571,10 +567,10 @@ def constructor_impl() -> Generator[str, None, None]:
                 yield f'this.{self.str_prop} = {self.str_prop};'
 
         if 'constructor' in self.overrides_:
-            yield from self.overrides_.pop('constructor').transpile({
-                **self.context,
-                'default_impl': self.get_lines(constructor_impl())
-            })
+            yield from self.transpile_override(
+                'constructor',
+                constructor_impl()
+            )
         else:
             yield f'constructor ({", ".join(props)}) {{'
             self.indent()
@@ -592,10 +588,7 @@ def ci_compare(self) -> Generator[Optional[str], None, None]:
             "=== 0 : a === b;"
         )
         if 'ciCompare' in self.overrides_:
-            yield from self.overrides_.pop('ciCompare').transpile({
-                **self.context,
-                'default_impl': SafeString(self.get_line(impl))
-            })
+            yield from self.transpile_override('ciCompare', impl)
         else:
             yield 'static ciCompare(a, b) {'
             self.indent()
@@ -616,10 +609,7 @@ def to_string(  # pylint: disable=W0613
         """
         impl = f'return this.{self.str_prop};'
         if 'toString' in self.overrides_:
-            yield from self.overrides_.pop('toString').transpile({
-                **self.context,
-                'default_impl': self.get_line(impl)
-            })
+            yield from self.transpile_override('toString', impl)
         else:
             yield 'toString() {'
             self.indent()
@@ -699,10 +689,7 @@ def iterator(
         enums = [f'{self.class_name}.{enm.name}' for enm in enum]
         impl = f'return [{", ".join(enums)}][Symbol.iterator]();'
         if '[Symbol.iterator]' in self.overrides_:
-            yield from self.overrides_.pop('[Symbol.iterator]').transpile({
-                **self.context,
-                'default_impl': self.get_line(impl)
-            })
+            yield from self.transpile_override('[Symbol.iterator]', impl)
         else:
             yield 'static [Symbol.iterator]() {'
             self.indent()