Method update

mypy/server/update.py:208–305

Update previous build result by processing changed modules. Also propagate changes to other modules as needed, but only process those parts of other modules that are affected by the changes. Retain the existing ASTs and symbol tables of unaffected modules. Reuses or

(
        self,
        changed_modules: list[tuple[str, str]],
        removed_modules: list[tuple[str, str]],
        followed: bool = False,
    )

        self.processed_targets: list[str] = []

    def update(
        self,
        changed_modules: list[tuple[str, str]],
        removed_modules: list[tuple[str, str]],
        followed: bool = False,
    ) -> list[str]:
        """Update previous build result by processing changed modules.

        Also propagate changes to other modules as needed, but only process
        those parts of other modules that are affected by the changes. Retain
        the existing ASTs and symbol tables of unaffected modules.

        Reuses original BuildManager and Graph.

        Args:
            changed_modules: Modules changed since the previous update/build; each is
                a (module id, path) tuple. Includes modified and added modules.
                Assume this is correct; it's not validated here.
            removed_modules: Modules that have been deleted since the previous update
                or removed from the build.
            followed: If True, the modules were found through following imports

        Returns:
            A list of errors.
        """
        self.processed_targets.clear()
        changed_modules = changed_modules + removed_modules
        removed_set = {module for module, _ in removed_modules}
        self.changed_modules = changed_modules

        if not changed_modules:
            return self.previous_messages

        # Reset find_module's caches for the new build.
        self.manager.find_module_cache.clear()

        self.triggered = []
        self.updated_modules = []
        changed_modules = dedupe_modules(changed_modules + self.stale)
        initial_set = {id for id, _ in changed_modules}
        self.manager.log_fine_grained(
            "==== update %s ====" % ", ".join(repr(id) for id, _ in changed_modules)
        )
        if self.previous_targets_with_errors and is_verbose(self.manager):
            self.manager.log_fine_grained(
                "previous targets with errors: %s" % sorted(self.previous_targets_with_errors)
            )

        blocking_error = None
        if self.blocking_error:
            # Handle blocking errors first. We'll exit as soon as we find a
            # module that still has blocking errors.
            self.manager.log_fine_grained(f"existing blocker: {self.blocking_error[0]}")
            changed_modules = dedupe_modules([self.blocking_error] + changed_modules)
            blocking_error = self.blocking_error[0]
            self.blocking_error = None

        while True: