Merge pull request #265 from openzim/wabac_changes

Backport wabac changes

Author: benoit74

src/zimscraperlib/rewriting/js.py

@@ -11,6 +11,10 @@
 it appropriately
 - a specific JS file (provided in `statics` folder) for JS modules is included in the
 ZIM at `_zim_static/__wb_module_decl.js`
+
+This code is based on https://github.com/webrecorder/wabac.js/blob/main/src/rewrite/jsrewriter.ts
+Last backport of upstream changes is from Sept 13, 2025
+Commit 6dd2d9ae664cfcd2ea8637d7d6c7ed7a0ca332a0
 """
 
 import re
@@ -29,13 +33,13 @@
 from zimscraperlib.rewriting.url_rewriting import ArticleUrlRewriter, ZimPath
 
 # The regex used to rewrite `import ...` in module code.
-IMPORT_MATCH_RX = re.compile(
-    r"""^\s*?import(?:['"\s]*(?:[\w*${}\s,]+from\s*)?['"\s]?['"\s])(?:.*?)['"\s]""",
+IMPORT_EXPORT_MATCH_RX = re.compile(
+    r"""(^|;)\s*?(?:im|ex)port(?:['"\s]*(?:[\w*${}\s,]+from\s*)?['"\s]?['"\s])(?:.*?)['"\s]""",
 )
 
 # A sub regex used inside `import ...` rewrite to rewrite http url imported
-IMPORT_HTTP_RX = re.compile(
-    r"""(import(?:['"\s]*(?:[\w*${}\s,]+from\s*)?['"\s]?['"\s]))((?:https?|[./]).*?)(['"\s])""",
+IMPORT_EXPORT_HTTP_RX = re.compile(
+    r"""((?:im|ex)port(?:['"\s]*(?:[\w*${}\s,]+from\s*)?['"\s]?['"\s]))((?:https?|[./]).*?)(['"\s])""",
 )
 
 # This list of global variables we want to wrap.
@@ -153,7 +157,10 @@ def create_js_rules() -> list[TransformationRule]:
 
     return [
         # rewriting `eval(...)` - invocation
-        (re.compile(r"(?:^|\s)\beval\s*\("), replace_prefix_from(eval_str, "eval")),
+        (
+            re.compile(r"(?<!static)(?<!function)(?<!})(?:^|\s)\beval\s*\("),
+            replace_prefix_from(eval_str, "eval"),
+        ),
         (re.compile(r"\([\w]+,\s*eval\)\("), m2str(lambda _: f" {eval_str}")),
         # rewriting `x = eval` - no invocation
         (re.compile(r"[=]\s*\beval\b(?![(:.$])"), replace("eval", "self.eval")),
@@ -162,7 +169,7 @@ def create_js_rules() -> list[TransformationRule]:
         (re.compile(r"\.postMessage\b\("), add_prefix(".__WB_pmw(self)")),
         # rewriting `location = ` to custom expression `(...).href =` assignement
         (
-            re.compile(r"(?:^|[^$.+*/%^-])\s?\blocation\b\s*[=]\s*(?![\s\d=])"),
+            re.compile(r"(?:^|[^$.+*/%^-])\s?\blocation\b\s*[=]\s*(?![\s\d=>])"),
             add_suffix_non_prop(check_loc),
         ),
         # rewriting `return this`
@@ -312,8 +319,8 @@ def sub_funct(match: re.Match[str]) -> str:
                         f"{match.group(3)}"
                     )
 
-                return IMPORT_HTTP_RX.sub(sub_funct, m_object[0])
+                return IMPORT_EXPORT_HTTP_RX.sub(sub_funct, m_object[0])
 
             return func
 
-        return (IMPORT_MATCH_RX, rewrite_import())
+        return (IMPORT_EXPORT_MATCH_RX, rewrite_import())

tests/rewriting/test_js_rewriting.py

@@ -186,6 +186,10 @@ def wrap_script(text: str) -> str:
             "self.__WB_check_loc(location, argument"
             "s)) || {}).href = http://example.com/",
         ),
+        WrappedTestContent(
+            input_='location => "http://example.com/"',
+            expected='location => "http://example.com/"',
+        ),
         WrappedTestContent(
             input_=" location = http://example.com/2",
             expected=" location = ((self.__WB_check_loc && "
@@ -220,6 +224,24 @@ def wrap_script(text: str) -> str:
             expected="if (self.foo) { console.log('blah') }",
         ),
         WrappedTestContent(input_="window.x = 5", expected="window.x = 5"),
+        WrappedTestContent(
+            input_="""
+            class A {}
+            const B = 5;
+            let C = 4;
+            var D = 3;
+
+            location = "http://example.com/2" """,
+            expected="""
+            class A {}
+            const B = 5;
+            let C = 4;
+            var D = 3;
+
+            location = ((self.__WB_check_loc && """
+            "self.__WB_check_loc(location, arguments)) || {}).href "
+            """= "http://example.com/2" """,
+        ),
         WrappedTestContent(input_=" var    self  ", expected=" let    self  "),
     ]
 )
@@ -288,6 +310,20 @@ def wrap_import(text: str) -> str:
 export { a };
 """,
         ),
+        # rewrite import same line
+        ImportTestContent(
+            input_='import{A, B} from "https://example.com/";'
+            'import{C, D} from "https://example.org"',
+            expected='import{A, B} from "../../../example.com/";'
+            'import{C, D} from "../../../example.org/"',
+        ),
+        # rewrite import / export same line
+        ImportTestContent(
+            input_='import{A, B} from "https://example.com/";'
+            'export{C, D} from "/another/path/to/file"',
+            expected='import{A, B} from "../../../example.com/";'
+            'export{C, D} from "../../another/path/to/file"',
+        ),
         # rewrite ESM module import
         ImportTestContent(
             input_='import "https://example.com/file.js"',
@@ -387,6 +423,9 @@ def test_import_rewrite(rewrite_import_content: ImportTestContent):
         ",eval(a)",
         "this.$eval(a)",
         "x = $eval; x(a);",
+        "static eval(a,b){ }",
+        "function eval(a,b){ }",
+        "} eval(a,b){ }",
         "obj = { eval : 1 }",
         "x = obj.eval",
         "x = obj.eval(a)",