fix(#829): guard prefixed runtime variable launches

packages/mosaic/framework/tools/lease-broker/check-runtime-launches.py

@@ -79,7 +79,7 @@ DIRECT_PATTERNS: Final = (
     re.compile(r"\beval\s+[\"'](?:claude|pi)(?:\s|[\"'])"),
 )
 RUNTIME_ASSIGNMENT: Final = re.compile(
-    r"^\s*([A-Za-z_][A-Za-z0-9_]*)\s*=\s*[\"']?(?:claude|pi)(?:\s|[\"']|$)"
+    r"^\s*([A-Za-z_][A-Za-z0-9_]*)\s*=\s*[\"']?(?:claude|pi)(?:\s|[\"']|[;&|]|$)"
 )
 TYPESCRIPT_WRAPPER_INVOCATION: Final = re.compile(
     r"(?m)^\s*execRuntime\s*\(\s*[\"']python3[\"']\s*,\s*"
@@ -226,44 +226,71 @@ def is_gated_line(path: Path, line: str) -> bool:
     )
 
 
-def is_shell_direct_invocation(path: Path, line: str) -> bool:
+def shell_command_tokens(path: Path, line: str) -> list[str]:
     if path.suffix.lower() not in SHELL_SUFFIXES:
-        return False
+        return []
     assignment = re.compile(r"^[A-Za-z_][A-Za-z0-9_]*=")
     case_arm = re.match(r"^\s*[^;&()]+\)\s*", line)
     command_source = line[case_arm.end() :] if case_arm is not None else line
+    resolved: list[str] = []
     for command in shell_commands(command_source):
         index = 0
         while index < len(command) and assignment.match(command[index]):
             index += 1
-        while index < len(command) and command[index] in {"command", "exec", "nohup"}:
-            index += 1
-        if index < len(command) and command[index] == "env":
-            index += 1
-            while index < len(command) and (
-                command[index].startswith("-") or assignment.match(command[index])
-            ):
+        # Resolve command position once for every literal and variable caller.
+        # Prefixes may be nested in either order (for example `exec env A=1`).
+        while index < len(command):
+            if command[index] in {"command", "exec", "nohup"}:
                 index += 1
-            while index < len(command) and command[index] in {"command", "exec", "nohup"}:
+                continue
+            if command[index] == "env":
                 index += 1
-        if index < len(command) and Path(command[index]).name in {"claude", "pi"}:
-            return True
-    return False
+                while index < len(command) and (
+                    command[index].startswith("-") or assignment.match(command[index])
+                ):
+                    index += 1
+                continue
+            break
+        if index < len(command):
+            resolved.append(command[index])
+    return resolved
 
 
-def is_direct_line(path: Path, line: str) -> bool:
-    return is_shell_direct_invocation(path, line) or any(
+def runtime_variable_reference(token: str, runtime_variables: set[str]) -> bool:
+    match = re.fullmatch(r"\$(?:([A-Za-z_][A-Za-z0-9_]*)|\{([A-Za-z_][A-Za-z0-9_]*)\})", token)
+    if match is None:
+        return False
+    return (match.group(1) or match.group(2)) in runtime_variables
+
+
+def is_shell_direct_invocation(
+    path: Path, line: str, runtime_variables: set[str]
+) -> bool:
+    return any(
+        Path(token).name in {"claude", "pi"}
+        or runtime_variable_reference(token, runtime_variables)
+        for token in shell_command_tokens(path, line)
+    )
+
+
+def is_direct_line(path: Path, line: str, runtime_variables: set[str]) -> bool:
+    return is_shell_direct_invocation(path, line, runtime_variables) or any(
         pattern.search(line) for pattern in DIRECT_PATTERNS
     )
 
 
-def executes_runtime_variable(line: str, runtime_variables: set[str]) -> bool:
+def executes_runtime_variable(
+    path: Path, line: str, runtime_variables: set[str]
+) -> bool:
+    if any(
+        runtime_variable_reference(token, runtime_variables)
+        for token in shell_command_tokens(path, line)
+    ):
+        return True
     for variable in runtime_variables:
         reference = rf"\$(?:{re.escape(variable)}|\{{{re.escape(variable)}\}})"
         if re.search(rf"\beval\s+[\"']?{reference}", line):
             return True
-        if re.match(rf"^\s*[\"']?{reference}[\"']?(?:\s|$)", line):
-            return True
     return False
 
 
@@ -293,8 +320,8 @@ def classify_text(path: Path, source: str) -> list[LaunchSite]:
         if assignment is not None:
             runtime_variables.add(assignment.group(1))
         primitive_violation = DANGEROUS_PRIMITIVE in line and not is_choke_point(path)
-        line_is_direct = is_direct_line(path, line) or executes_runtime_variable(
-            line, runtime_variables
+        line_is_direct = is_direct_line(path, line, runtime_variables) or executes_runtime_variable(
+            path, line, runtime_variables
         )
         line_is_gated = line_number in validated_typescript_wrappers or is_gated_line(path, line)