[engine] Add ctx.io.tempfile method
This will be useful most notably for integrating with formatters that
don't have a dry-run mode. shac requires that formatter checks emit
the formatted result as a finding rather than writing the result at
runtime, so formatters that lack a dry run mode can now do:
def foo_fmt(ctx):
for path in ctx.scm.affected_files():
original = ctx.io.read_file(path)
temp = ctx.io.tempfile(ctx.io.read_file(path))
ctx.os.exec(["foo", "fmt", temp])
new = ctx.io.read_file(temp)
if new != original:
ctx.emit.finding(
filepath=path,
replacements=[ctx.io.read_file(temp)],
)
Change-Id: Ic6438a16a263f4250cb0c276fa988f89ac028101
Reviewed-on: https://fuchsia-review.googlesource.com/c/shac-project/shac/+/910595
Reviewed-by: Anthony Fandrianto <atyfto@google.com>
Commit-Queue: Auto-Submit <auto-submit@fuchsia-infra.iam.gserviceaccount.com>
Fuchsia-Auto-Submit: Oliver Newman <olivernewman@google.com>
diff --git a/doc/stdlib.md b/doc/stdlib.md
index 3998b6b..d372cf6 100644
--- a/doc/stdlib.md
+++ b/doc/stdlib.md
@@ -157,6 +157,7 @@
- read_file
- tempdir
+- tempfile
## ctx.io.read_file
@@ -189,6 +190,19 @@
Returns a new temporary directory.
+## ctx.io.tempfile
+
+Returns a new temporary file.
+
+### Arguments
+
+* **content**: String or bytes to populate the file with.
+* **name**: (optional) The basename to give the file. May contain path separators, in which case the file will be nested accordingly. Will be chosen randomly if not specified.
+
+### Returns
+
+Absolute path to the created file.
+
## ctx.os
ctx.os is the object that exposes the API to interact with the operating
diff --git a/doc/stdlib.star b/doc/stdlib.star
index 60bec72..9733799 100644
--- a/doc/stdlib.star
+++ b/doc/stdlib.star
@@ -183,6 +183,21 @@
pass
+def _ctx_io_tempfile(content, name):
+ """Returns a new temporary file.
+
+ Args:
+ content: String or bytes to populate the file with.
+ name: (optional) The basename to give the file. May contain path
+ separators, in which case the file will be nested accordingly. Will be
+ chosen randomly if not specified.
+
+ Returns:
+ Absolute path to the created file.
+ """
+ pass
+
+
def _ctx_os_exec(
cmd,
cwd = None,
@@ -374,6 +389,7 @@
io = struct(
read_file = _ctx_io_read_file,
tempdir = _ctx_io_tempdir,
+ tempfile = _ctx_io_tempfile,
),
# ctx.os is the object that exposes the API to interact with the operating
# system.
diff --git a/internal/engine/run_test.go b/internal/engine/run_test.go
index 81d1ddb..91063ce 100644
--- a/internal/engine/run_test.go
+++ b/internal/engine/run_test.go
@@ -1082,11 +1082,6 @@
" //ctx-immutable.star:17:6: in cb\n",
},
{
- "ctx-io-read_file-abs.star",
- "ctx.io.read_file: for parameter \"filepath\": \"/dev/null\" do not use absolute path",
- " //ctx-io-read_file-abs.star:16:19: in cb\n",
- },
- {
"ctx-io-read_file-dir.star",
"ctx.io.read_file: for parameter \"filepath\": \".\" is a directory",
" //ctx-io-read_file-dir.star:16:19: in cb\n",
@@ -1673,6 +1668,11 @@
}(),
},
{
+ "ctx-io-tempfile.star",
+ "[//ctx-io-tempfile.star:18] first\nfile\ncontents\n\n" +
+ "[//ctx-io-tempfile.star:19] contents\nof\nsecond\nfile\n\n",
+ },
+ {
"ctx-os-exec-10Mib.star",
"[//ctx-os-exec-10Mib.star:17] 0\n",
},
diff --git a/internal/engine/runtime_ctx.go b/internal/engine/runtime_ctx.go
index 942b431..ae0b0a8 100644
--- a/internal/engine/runtime_ctx.go
+++ b/internal/engine/runtime_ctx.go
@@ -33,6 +33,7 @@
"io": toValue("ctx.io", starlark.StringDict{
"read_file": newBuiltin("ctx.io.read_file", ctxIoReadFile),
"tempdir": newBuiltin("ctx.io.tempdir", ctxIoTempdir),
+ "tempfile": newBuiltin("ctx.io.tempfile", ctxIoTempfile),
}),
"os": toValue("ctx.os", starlark.StringDict{
"exec": newBuiltin("ctx.os.exec", ctxOsExec),
diff --git a/internal/engine/runtime_ctx_io.go b/internal/engine/runtime_ctx_io.go
index 94001d5..3767c17 100644
--- a/internal/engine/runtime_ctx_io.go
+++ b/internal/engine/runtime_ctx_io.go
@@ -46,9 +46,13 @@
if !ok {
return nil, fmt.Errorf("for parameter \"size\": %s is an invalid size", argsize)
}
- dst, err := absPath(string(argfilepath), filepath.Join(s.root, s.subdir))
- if err != nil {
- return nil, fmt.Errorf("for parameter \"filepath\": %s %w", argfilepath, err)
+ dst := string(argfilepath)
+ if !filepath.IsAbs(dst) {
+ var err error
+ dst, err = absPath(dst, filepath.Join(s.root, s.subdir))
+ if err != nil {
+ return nil, fmt.Errorf("for parameter \"filepath\": %s %w", argfilepath, err)
+ }
}
b, err := readFileImpl(dst, size)
if err != nil {
@@ -74,6 +78,48 @@
return starlark.String(t), err
}
+// ctxIoTempfile implements native function ctx.io.tempfile().
+//
+// Make sure to update //doc/stdlib.star whenever this function is modified.
+func ctxIoTempfile(ctx context.Context, s *shacState, name string, args starlark.Tuple, kwargs []starlark.Tuple) (starlark.Value, error) {
+ var argcontent starlark.Value
+ var argname starlark.String = "00001"
+ if err := starlark.UnpackArgs(name, args, kwargs,
+ "content", &argcontent,
+ "name?", &argname,
+ ); err != nil {
+ return nil, err
+ }
+ var content []byte
+ switch v := argcontent.(type) {
+ case starlark.Bytes:
+ content = unsafeByteSlice(string(v))
+ case starlark.String:
+ content = unsafeByteSlice(string(v))
+ default:
+ return nil, fmt.Errorf("for parameter \"content\": got %s, want str or bytes", argcontent.Type())
+ }
+
+ // TODO(olivernewman): Consider not creating a new dir for every temp file.
+ dir, err := s.newTempDir()
+ if err != nil {
+ return nil, err
+ }
+ if filepath.IsAbs(string(argname)) {
+ return nil, fmt.Errorf("for parameter \"name\": absolute paths are not allowed")
+ }
+
+ path := filepath.Join(dir, string(argname))
+ if err = os.MkdirAll(filepath.Dir(path), 0o700); err != nil {
+ return nil, err
+ }
+
+ if err = os.WriteFile(path, content, 0o600); err != nil {
+ return nil, err
+ }
+ return starlark.String(path), err
+}
+
// Support functions.
// readFileImpl is similar to os.ReadFile() albeit it limits the amount of data
diff --git a/internal/engine/runtime_shac.go b/internal/engine/runtime_shac.go
index 0704fe1..86756e7 100644
--- a/internal/engine/runtime_shac.go
+++ b/internal/engine/runtime_shac.go
@@ -27,7 +27,7 @@
// Version is the current tool version.
//
// TODO(maruel): Add proper version, preferably from git tag.
- Version = [...]int{0, 1, 2}
+ Version = [...]int{0, 1, 3}
)
// getShac returns the global shac object.
diff --git a/internal/engine/testdata/fail_or_throw/ctx-io-read_file-abs.star b/internal/engine/testdata/print/ctx-io-tempfile.star
similarity index 74%
rename from internal/engine/testdata/fail_or_throw/ctx-io-read_file-abs.star
rename to internal/engine/testdata/print/ctx-io-tempfile.star
index 8797962..59fe1b2 100644
--- a/internal/engine/testdata/fail_or_throw/ctx-io-read_file-abs.star
+++ b/internal/engine/testdata/print/ctx-io-tempfile.star
@@ -13,6 +13,9 @@
# limitations under the License.
def cb(ctx):
- ctx.io.read_file("/dev/null")
+ first = ctx.io.tempfile("first\nfile\ncontents\n")
+ second = ctx.io.tempfile(b"contents\nof\nsecond\nfile\n", name="dir/second.txt")
+ print(ctx.io.read_file(first))
+ print(ctx.io.read_file(second))
shac.register_check(cb)
