diff options
| -rw-r--r-- | src/io/fs/readfile.go | 3 | ||||
| -rw-r--r-- | src/testing/fstest/testfs.go | 12 |
2 files changed, 15 insertions, 0 deletions
diff --git a/src/io/fs/readfile.go b/src/io/fs/readfile.go index 7ee9eadac4..d3c181c0a9 100644 --- a/src/io/fs/readfile.go +++ b/src/io/fs/readfile.go @@ -15,6 +15,9 @@ type ReadFileFS interface { // A successful call returns a nil error, not io.EOF. // (Because ReadFile reads the whole file, the expected EOF // from the final Read is not treated as an error to be reported.) + // + // The caller is permitted to modify the returned byte slice. + // This method should return a copy of the underlying data. ReadFile(name string) ([]byte, error) } diff --git a/src/testing/fstest/testfs.go b/src/testing/fstest/testfs.go index 80ca0e9a1d..5c4f30af16 100644 --- a/src/testing/fstest/testfs.go +++ b/src/testing/fstest/testfs.go @@ -537,6 +537,18 @@ func (t *fsTester) checkFile(file string) { } t.checkFileRead(file, "ReadAll vs fsys.ReadFile", data, data2) + // Modify the data and check it again. Modifying the + // returned byte slice should not affect the next call. + for i := range data2 { + data2[i]++ + } + data2, err = fsys.ReadFile(file) + if err != nil { + t.errorf("%s: second call to fsys.ReadFile: %v", file, err) + return + } + t.checkFileRead(file, "Readall vs second fsys.ReadFile", data, data2) + t.checkBadPath(file, "ReadFile", func(name string) error { _, err := fsys.ReadFile(name); return err }) } |