closewrite

Documentation

Overview

Package closewrite provides a go/analysis analyzer that reports a discarded Close error on a file opened for WRITING.

Close is where a write is finally decided. The kernel may defer the failure of an earlier Write until the descriptor is closed — a full disk, a quota, a dropped network filesystem — so a discarded Close error on a written file is the program declaring success over a file that may be truncated, empty, or absent. Eight such defects were found by hand across this fleet; six were real data loss, and every one of them read as a routine `defer f.Close()`.

The rule is deliberately narrow, because a gate that cries wolf is worse than no gate. It fires only where the file's own creation proves the intent to write: os.Create, os.CreateTemp, or os.OpenFile with a write flag. A reader's Close is never reported — nothing is lost by failing to close a file you only read — which keeps the overwhelmingly common `defer f.Close()` after os.Open silent, exactly as it should be.

Index

• Variables

Variables

var Analyzer = &analysis.Analyzer{
	Name:     "closewrite",
	Doc:      "reports a discarded Close error on a file opened for writing, where the loss is real data",
	Requires: []*analysis.Analyzer{inspect.Analyzer},
	Run:      run,
}

Analyzer reports discarded Close errors on files opened for writing.

var Registration = goyze.Registration{
	Name:       "closewrite",
	Categories: []goyze.Category{"errors"},
	URL:        "https://docs.gomatic.dev/yze/closewrite",
	Analyzer:   Analyzer,
}

Registration declares this analyzer to the yze framework.