Custom Filesystems

Overview

gogenfilter uses Go’s fs.FS interface, making it easy to test without real files or to read from custom sources.

Default Behavior

By default, the filter uses os.DirFS(".") (the current working directory):

f := gogenfilter.NewFilter(
    gogenfilter.Enabled(),
    gogenfilter.WithFilterOptions(gogenfilter.FilterAll),
)
// Uses os.DirFS(".") internally

Testing with MapFS

Use fstest.MapFS for deterministic, isolated tests:

import "testing/fstest"

mapFS := fstest.MapFS{
    "db/models.go": &fstest.MapFile{
        Data: []byte("// Code generated by sqlc. DO NOT EDIT.\npackage db\n"),
    },
    "main.go": &fstest.MapFile{
        Data: []byte("package main\n"),
    },
}

f := gogenfilter.NewFilter(
    gogenfilter.Enabled(),
    gogenfilter.WithFilterOptions(gogenfilter.FilterSQLC),
    gogenfilter.WithFS(mapFS),
)

filtered, _ := f.ShouldFilter("db/models.go") // true
filtered, _ = f.ShouldFilter("main.go")       // false

Custom Filesystem

Implement fs.FS for any source — embedded files, archives, remote storage:

// With embed.FS
//go:embed testdata/*
var testdata embed.FS

f := gogenfilter.NewFilter(
    gogenfilter.Enabled(),
    gogenfilter.WithFilterOptions(gogenfilter.FilterAll),
    gogenfilter.WithFS(testdata),
)

nil Handling

Passing nil to WithFS is safe — the filter falls back to os.DirFS(".").