feat: allow host in dsn and use statement based transactions (#10)

* feat: support more options in dsn

* test: add tests with mock server

* refactor: transactions

* feat: add comments parser

* feat: parse parameters correctly

* feat: support null params

* test: add more tests

* docs: add comments

* build: fix integration tests + add GitHub actions

* build: copy testutil to sql-driver and update Spanner version

* chore: update copyright year

* fix: address review comments

.github/workflows/unit-tests.yml

@@ -0,0 +1,18 @@
+on: [push, pull_request]
+name: Unit Tests
+jobs:
+  test:
+    strategy:
+      matrix:
+        go-version: [1.15.x, 1.16.x]
+        os: [ubuntu-latest, macos-latest, windows-latest]
+    runs-on: ${{ matrix.os }}
+    steps:
+      - name: Install Go
+        uses: actions/setup-go@v2
+        with:
+          go-version: ${{ matrix.go-version }}
+      - name: Checkout code
+        uses: actions/checkout@v2
+      - name: Run unit tests
+        run: go test -short

.gitignore

@@ -1 +1,2 @@
-gorm/
+gorm/
+.idea

README.md

@@ -73,36 +73,16 @@ $ export SPANNER_EMULATOR_HOST=localhost:9010
 
 ## Troubleshooting
 
-This driver shouldn't automatically retry the transactions but it does.
-It causes unwanted results. Don't use this library in production yet.
+The driver will propagate any Aborted error that is returned by Cloud Spanner
+during a read/write transaction, and it will currently not automatically retry
+the transaction.
 
 ---
 
 gorm cannot use the driver as it-is but @rakyll has been working on a dialect.
 She doesn't have bandwidth to ship a fully featured dialect right now but contact
 her if you would like to contribute.
 
----
-
-`error = <use T(nil), not nil>`: Use a typed nil, instead of just nil.
-
-The following query returns rows with NULL likes:
-
-``` go
-var nilInt64 *int64
-db.QueryContext(ctx, "SELECT id, text FROM tweets WHERE likes = @likes LIMIT 10", nilInt64)
-```
-
----
-
-When querying and executing with emails, pass them as arguments and don't hardcode
-them in the query:
-
-``` go
-db.QueryContext(ctx, "SELECT id, name ... WHERE email = @email", "[email protected]")
-```
-
-The driver will relax this requirement in the future but it is a work-in-progress for now.
 
 ---