feat: Handle default database paths better (#878)

* return the path in the error message
* specify defaults for `decrypt()` and `subscribe()`

Closes #868

CHANGELOG.md

@@ -6,6 +6,10 @@
 
 ## Push
 
+### What's new
+
+- PushAPI now defines a number of default parameters for functions ([#868](https://github.com/mozilla/application-services/issues/868))
+
 ### Breaking changes
 
 - `mozilla.appservices.push.BridgeTypes` is now

components/push/android/src/main/java/mozilla/appservices/push/PushManager.kt

@@ -290,12 +290,12 @@ interface PushAPI : java.lang.AutoCloseable {
      * Get the Subscription Info block
      *
      * @param channelID Channel ID (UUID4) for new subscription, either pre-generated or "" and one will be created.
-     * @param scope Site scope string.
+     * @param scope Site scope string (defaults to "" for no site scope string).
      * @return a SubscriptionInfo structure
      */
     fun subscribe(
         channelID: String = "",
-        scope: String
+        scope: String = ""
     ): SubscriptionInfo
 
     /**
@@ -342,17 +342,17 @@ interface PushAPI : java.lang.AutoCloseable {
      *
      * @param channelID: the ChannelID (included in the envelope of the message)
      * @param body: The encrypted body of the message
-     * @param encoding: The Content Encoding "enc" field of the message
-     * @param salt: The "salt" field (if present in the raw message)
-     * @param dh: the "dh" field (if present in the raw message)
+     * @param encoding: The Content Encoding "enc" field of the message (defaults to "aes128gcm")
+     * @param salt: The "salt" field (if present in the raw message, defaults to "")
+     * @param dh: the "dh" field (if present in the raw message, defaults to "")
      * @return Decrypted message body.
      */
     fun decrypt(
         channelID: String,
         body: String,
-        encoding: String,
-        salt: String,
-        dh: String
+        encoding: String = "aes128gcm",
+        salt: String = "",
+        dh: String = ""
     ): ByteArray
 
     /** get the dispatch info for a given subscription channel

components/push/android/src/test/java/mozilla/appservices/push/PushTest.kt

@@ -211,4 +211,18 @@ class PushTest {
         assertEquals("uaid", "abad1d3a00000000aabbccdd00000000", dispatch.uaid)
         assertEquals("scope", "foo", dispatch.scope)
     }
+
+    @Test
+    fun testValidPath() {
+        try {
+            PushManager(
+                senderId = mockSenderId,
+                bridgeType = BridgeType.TEST,
+                registrationId = "TestRegistrationId",
+                databasePath = "/dev/false"
+            )
+        } catch (e: PushError) {
+            assert(e is StorageError)
+        }
+    }
 }

components/push/storage/src/db.rs

@@ -3,7 +3,7 @@ use std::{ops::Deref, path::Path};
 use rusqlite::Connection;
 use sql_support::ConnExt;
 
-use push_errors::Result;
+use push_errors::{ErrorKind, Result};
 
 use crate::{record::PushRecord, schema};
 
@@ -39,7 +39,16 @@ impl PushDb {
     }
 
     pub fn open(path: impl AsRef<Path>) -> Result<Self> {
-        Ok(Self::with_connection(Connection::open(path)?)?)
+        // By default, file open errors are StorageSqlErrors and aren't super helpful.
+        // Instead, remap to StorageError and provide the path to the file that couldn't be opened.
+        Ok(Self::with_connection(Connection::open(&path).map_err(
+            |_| {
+                ErrorKind::StorageError(format!(
+                    "Could not open database file {:?}",
+                    &path.as_ref().as_os_str()
+                ))
+            },
+        )?)?)
     }
 
     pub fn open_in_memory() -> Result<Self> {