From 2a8330a90dab5c7dd6aa76bfb376fd97eccd00e5 Mon Sep 17 00:00:00 2001
From: Janis Danisevskis <jdanis@google.com>
Date: Wed, 20 Jan 2021 15:34:26 -0800
Subject: [PATCH] Keystore 2.0: Move test utils to separate library.

Move TempDir test utils to separate library for easier reuse.

Test: keystore2_test
Change-Id: If1edfde39b66efa43f8a5ed32a500fad57291512
---
 keystore2/Android.bp                          | 11 ++++++++++
 keystore2/src/database.rs                     |  2 +-
 keystore2/src/legacy_blob.rs                  |  2 +-
 keystore2/src/lib.rs                          |  5 -----
 .../{src/test/utils.rs => test_utils/lib.rs}  | 20 +++++++++++++++++++
 5 files changed, 33 insertions(+), 7 deletions(-)
 rename keystore2/{src/test/utils.rs => test_utils/lib.rs} (67%)

diff --git a/keystore2/Android.bp b/keystore2/Android.bp
index 2ed2a60f..70363ef4 100644
--- a/keystore2/Android.bp
+++ b/keystore2/Android.bp
@@ -40,6 +40,16 @@ rust_library {
     ],
 }
 
+rust_library {
+    name: "libkeystore2_test_utils",
+    crate_name: "keystore2_test_utils",
+    srcs: ["test_utils/lib.rs"],
+    rustlibs: [
+        "liblog_rust",
+        "librand",
+    ]
+}
+
 rust_test {
     name: "keystore2_test",
     crate_name: "keystore2",
@@ -60,6 +70,7 @@ rust_test {
         "libkeystore2_crypto_rust",
         "libkeystore2_km_compat",
         "libkeystore2_selinux",
+        "libkeystore2_test_utils",
         "liblazy_static",
         "liblibc",
         "liblibsqlite3_sys",
diff --git a/keystore2/src/database.rs b/keystore2/src/database.rs
index 344fe2fc..225378f4 100644
--- a/keystore2/src/database.rs
+++ b/keystore2/src/database.rs
@@ -1792,7 +1792,7 @@ mod tests {
     };
     use crate::key_perm_set;
     use crate::permission::{KeyPerm, KeyPermSet};
-    use crate::test::utils::TempDir;
+    use keystore2_test_utils::TempDir;
     use android_hardware_security_keymint::aidl::android::hardware::security::keymint::{
         HardwareAuthToken::HardwareAuthToken,
         HardwareAuthenticatorType::HardwareAuthenticatorType as kmhw_authenticator_type,
diff --git a/keystore2/src/legacy_blob.rs b/keystore2/src/legacy_blob.rs
index 34a0ecab..230a82cb 100644
--- a/keystore2/src/legacy_blob.rs
+++ b/keystore2/src/legacy_blob.rs
@@ -775,7 +775,7 @@ mod test {
     mod legacy_blob_test_vectors;
     use crate::error;
     use crate::legacy_blob::test::legacy_blob_test_vectors::*;
-    use crate::test::utils::TempDir;
+    use keystore2_test_utils::TempDir;
 
     #[test]
     fn decode_encode_alias_test() {
diff --git a/keystore2/src/lib.rs b/keystore2/src/lib.rs
index 0475d6ff..811db91b 100644
--- a/keystore2/src/lib.rs
+++ b/keystore2/src/lib.rs
@@ -34,8 +34,3 @@ mod async_task;
 mod db_utils;
 mod gc;
 mod super_key;
-
-#[cfg(test)]
-mod test {
-    pub mod utils;
-}
diff --git a/keystore2/src/test/utils.rs b/keystore2/test_utils/lib.rs
similarity index 67%
rename from keystore2/src/test/utils.rs
rename to keystore2/test_utils/lib.rs
index 8c938596..627af20c 100644
--- a/keystore2/src/test/utils.rs
+++ b/keystore2/test_utils/lib.rs
@@ -12,11 +12,14 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+//! Implements TempDir which aids in creating an cleaning up temporary directories for testing.
+
 use std::fs::{create_dir, remove_dir_all};
 use std::io::ErrorKind;
 use std::path::{Path, PathBuf};
 use std::{env::temp_dir, ops::Deref};
 
+/// Represents the lifecycle of a temporary directory for testing.
 #[derive(Debug)]
 pub struct TempDir {
     path: std::path::PathBuf,
@@ -24,6 +27,11 @@ pub struct TempDir {
 }
 
 impl TempDir {
+    /// Creates a temporary directory with a name of the form <prefix>_NNNNN where NNNNN is a zero
+    /// padded random number with 5 figures. The prefix must not contain file system separators.
+    /// The location of the directory cannot be chosen.
+    /// The directory with all of its content is removed from the file system when the resulting
+    /// object gets dropped.
     pub fn new(prefix: &str) -> std::io::Result<Self> {
         let tmp = loop {
             let mut tmp = temp_dir();
@@ -40,10 +48,20 @@ impl TempDir {
         Ok(Self { path: tmp, do_drop: true })
     }
 
+    /// Returns the absolute path of the temporary directory.
     pub fn path(&self) -> &Path {
         &self.path
     }
 
+    /// Returns a path builder for convenient extension of the path.
+    ///
+    /// ## Example:
+    ///
+    /// ```
+    /// let tdir = TempDir::new("my_test")?;
+    /// let temp_foo_bar = tdir.build().push("foo").push("bar");
+    /// ```
+    /// `temp_foo_bar` derefs to a Path that represents "<tdir.path()>/foo/bar"
     pub fn build(&self) -> PathBuilder {
         PathBuilder(self.path.clone())
     }
@@ -66,9 +84,11 @@ impl Drop for TempDir {
     }
 }
 
+/// Allows for convenient building of paths from a TempDir. See TempDir.build() for more details.
 pub struct PathBuilder(PathBuf);
 
 impl PathBuilder {
+    /// Adds another segment to the end of the path. Consumes, modifies and returns self.
     pub fn push(mut self, segment: &str) -> Self {
         self.0.push(segment);
         self