snapshot of https://github.com/zulip/zulip.git @ 48c69911c7dd4e03b20552eb3bd77ad8151c1357 (2026-09-15)

tools/lib/pretty_print.py

@@ -0,0 +1,197 @@
+import subprocess
+
+from zulint.printer import BOLDRED, CYAN, ENDC, GREEN
+
+from .template_parser import Token
+
+
+def shift_indents_to_the_next_tokens(tokens: list[Token]) -> None:
+    """
+    During the parsing/validation phase, it's useful to have separate
+    tokens for "indent" chunks, but during pretty printing, we like
+    to attach an `.indent` field to the substantive node, whether
+    it's an HTML tag or template directive or whatever.
+    """
+    tokens[0].indent = ""
+
+    for i, token in enumerate(tokens[:-1]):
+        next_token = tokens[i + 1]
+
+        if token.kind == "indent":
+            next_token.indent = token.s
+            token.new_s = ""
+
+        if token.kind == "newline" and next_token.kind != "indent":
+            next_token.indent = ""
+
+
+def token_allows_children_to_skip_indents(token: Token) -> bool:
+    # To avoid excessive indentation in templates with other
+    # conditionals, we don't require extra indentation for template
+    # logic blocks don't contain further logic as direct children.
+
+    # Each blocks are excluded from this rule, since we want loops to
+    # stand out.
+    if token.tag == "each":
+        return False
+
+    return token.kind in ("django_start", "handlebars_start") or token.tag == "a"
+
+
+def adjust_block_indentation(tokens: list[Token], fn: str) -> None:
+    start_token: Token | None = None
+
+    for token in tokens:
+        if token.kind in ("indent", "whitespace", "newline"):
+            continue
+
+        if token.tag in ("code", "pre"):
+            continue
+
+        # print(token.line, repr(start_token.indent) if start_token else "?", repr(token.indent), token.s, token.end_token and "start", token.start_token and "end")
+
+        if token.tag == "else":
+            assert token.start_token
+            if token.indent is not None:
+                token.indent = token.start_token.indent
+            continue
+
+        if start_token and token.indent is not None:
+            if (
+                not start_token.indent_is_final
+                and token.indent == start_token.orig_indent
+                and token_allows_children_to_skip_indents(start_token)
+            ):
+                start_token.child_indent = start_token.indent
+            start_token.indent_is_final = True
+
+        # Detect start token by its having a end token
+        if token.end_token:
+            if token.indent is not None:
+                token.orig_indent = token.indent
+                if start_token:
+                    assert start_token.child_indent is not None
+                    token.indent = start_token.child_indent
+                else:
+                    token.indent = ""
+                token.child_indent = token.indent + "    "
+            token.parent_token = start_token
+            start_token = token
+            continue
+
+        # Detect end token by its having a start token
+        if token.start_token:
+            if start_token != token.start_token:
+                raise AssertionError(
+                    f"""
+                    {token.kind} was unexpected in {token.s}
+                    in row {token.line} of {fn}
+                    """
+                )
+
+            if token.indent is not None:
+                token.indent = start_token.indent
+            start_token = start_token.parent_token
+            continue
+
+        if token.indent is None:
+            continue
+
+        if start_token is None:
+            token.indent = ""
+            continue
+
+        if start_token.child_indent is not None:
+            token.indent = start_token.child_indent
+
+
+def fix_indents_for_multi_line_tags(tokens: list[Token]) -> None:
+    def fix(frag: str) -> str:
+        frag = frag.strip()
+        return continue_indent + frag if frag else ""
+
+    for token in tokens:
+        if token.kind == "code":
+            continue
+
+        if token.line_span == 1 or token.indent is None:
+            continue
+
+        if token.kind in ("django_comment", "handlebars_comment", "html_comment", "text"):
+            continue_indent = token.indent
+        else:
+            continue_indent = token.indent + "  "
+
+        frags = token.new_s.split("\n")
+
+        token.new_s = frags[0] + "\n" + "\n".join(fix(frag) for frag in frags[1:])
+
+
+def apply_token_indents(tokens: list[Token]) -> None:
+    for token in tokens:
+        if token.indent:
+            token.new_s = token.indent + token.new_s
+
+
+def pretty_print_html(tokens: list[Token], fn: str) -> str:
+    for token in tokens:
+        token.new_s = token.s
+
+    shift_indents_to_the_next_tokens(tokens)
+    adjust_block_indentation(tokens, fn)
+    fix_indents_for_multi_line_tags(tokens)
+    apply_token_indents(tokens)
+
+    return "".join(token.new_s for token in tokens)
+
+
+def numbered_lines(s: str) -> str:
+    return "".join(f"{i + 1: >5} {line}\n" for i, line in enumerate(s.split("\n")))
+
+
+def validate_indent_html(fn: str, tokens: list[Token], fix: bool) -> bool:
+    with open(fn) as f:
+        html = f.read()
+    phtml = pretty_print_html(tokens, fn)
+    if html.split("\n") != phtml.split("\n"):
+        if fix:
+            print(GREEN + f"Automatically fixing indentation for {fn}" + ENDC)
+            with open(fn, "w") as f:
+                f.write(phtml)
+            # Since we successfully fixed the issues, we return True.
+            return True
+        print(
+            f"""
+{BOLDRED}PROBLEM{ENDC}: formatting errors in {fn}
+
+Here is how we would like you to format
+{CYAN}{fn}{ENDC}:
+---
+{numbered_lines(phtml)}
+---
+
+Here is the diff that you should either execute in your editor
+or apply automatically with the --fix option.
+
+({CYAN}Scroll up{ENDC} to see how we would like the file formatted.)
+
+Proposed {BOLDRED}diff{ENDC} for {CYAN}{fn}{ENDC}:
+            """,
+            flush=True,
+        )
+        subprocess.run(["diff", fn, "-"], input=phtml, text=True, check=False)
+        print(
+            f"""
+---
+
+{BOLDRED}PROBLEM!!!{ENDC}
+
+    You have formatting errors in {CYAN}{fn}{ENDC}
+    (Usually these messages are related to indentation.)
+
+This problem can be fixed with the {CYAN}`--fix`{ENDC} option.
+Scroll up for more details about {BOLDRED}what you need to fix ^^^{ENDC}.
+            """
+        )
+        return False
+    return True