Adding Optional bats-core Extensions (#10)

* Updating README to use newest tag of bazel-bats.
Moving SHA into its own var, similar to the version number.

* Updating `bazel_bats_dependencies()`'s default version value (and
corresponding SHA) to 1.7.0 (latest bats-core version).
Updating WORKSPACE to be more explicit in versions used.
Adding param checking to ensure that the SHA was passed in.
Updating README to show explicit version passing.

* Extending `bazel_bats_dependencies()` to also (optionally) allow for adding in bats extensions, bats-assert and bats-support (bats-support is required for bats-assert).
The decision to make these optional additions was made to not force extra dependencies on any downstream library that does not make use of them (dep management is good).
The `bats_test()` rule will be updated in a follow-up PR.

* Fixing missing comma.

* Slight cleanup on `if`s.

* * More better words (improving error messages).

* * Fixing nit.

* * Fixing nit 2.

* * Fixing nit 3.

* * More nit fix.

README.md

@@ -28,17 +28,27 @@ load("@bazel_bats//:deps.bzl", "bazel_bats_dependencies")
 bazel_bats_dependencies()
 ```
 
-You can alternatively specify the specific bats-core version.
+You can alternatively specify the specific bats-core version, as well as optionally adding bats-core extensions.
 
 ```
+BATS_ASSERT_VERSION = "2.0.0"
+BATS_ASSERT_SHA256 = "15dbf1abb98db785323b9327c86ee2b3114541fe5aa150c410a1632ec06d9903"
 BATS_CORE_VERSION = "1.7.0"
 BATS_CORE_SHA256 = "ac70c2a153f108b1ac549c2eaa4154dea4a7c1cc421e3352f0ce6ea49435454e"
+BATS_SUPPORT_VERSION = "0.3.0"
+BATS_SUPPORT_SHA256 = "7815237aafeb42ddcc1b8c698fc5808026d33317d8701d5ec2396e9634e2918f"
 
 # ...
 
 bazel_bats_dependencies(
     version = BATS_CORE_VERSION,
-    sha256 = BATS_CORE_SHA256)
+    sha256 = BATS_CORE_SHA256,
+    # Optional test extensions
+    bats_assert_version = BATS_ASSERT_VERSION,
+    bats_assert_sha256 = BATS_ASSERT_SHA256,
+    bats_support_version = BATS_SUPPORT_VERSION,
+    bats_support_sha256 = BATS_SUPPORT_SHA256
+)
 ```
 
 In your `BUILD.bazel` file add the following:

deps.bzl

@@ -2,7 +2,7 @@
 # https://stackoverflow.com/questions/47192668/idiomatic-retrieval-of-the-bazel-execution-path#
 load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
 
-BATS_CORE_BUILD="""
+_BATS_CORE_BUILD = """
 sh_library(
     name = "bats_lib",
     srcs = glob(["libexec/**"]),
@@ -69,19 +69,74 @@ sh_library(
 exports_files(glob(["test/*.bats"]))
 """
 
+_BATS_ASSERT_BUILD = """
+filegroup(
+    name = "load_files",
+    srcs = [
+        "load.bash",
+        "src/assert.bash",
+    ],
+    visibility = ["//visibility:public"],
+)
+"""
+
+_BATS_SUPPORT_BUILD = """
+filegroup(
+    name = "load_files",
+    srcs = [
+        "load.bash",
+        "src/error.bash",
+        "src/lang.bash",
+        "src/output.bash",
+    ],
+    visibility = ["//visibility:public"],
+)
+"""
+
 def bazel_bats_dependencies(
     version = "1.7.0",
-    sha256 = "ac70c2a153f108b1ac549c2eaa4154dea4a7c1cc421e3352f0ce6ea49435454e"
+    sha256 = "ac70c2a153f108b1ac549c2eaa4154dea4a7c1cc421e3352f0ce6ea49435454e",
+    bats_assert_version = None,
+    bats_assert_sha256 = None,
+    bats_support_version = None,
+    bats_support_sha256 = None
 ):
     if not sha256:
         fail("sha256 for bats-core was not supplied.")
 
     http_archive(
         name = "bats_core",
-        build_file_content = BATS_CORE_BUILD,
+        build_file_content = _BATS_CORE_BUILD,
         urls = [
             "https://github.com/bats-core/bats-core/archive/refs/tags/v%s.tar.gz" % version,
         ],
         strip_prefix = "bats-core-%s" % version,
         sha256 = sha256,
     )
+
+    if bats_assert_version:
+        if not bats_support_version:
+            fail("bats-assert version was set, but was missing set version for dependency bats-support.")
+        if not bats_assert_sha256:
+            fail("sha256 for bats-assert was not supplied.")
+        http_archive(
+            name = "bats_assert",
+            build_file_content = _BATS_ASSERT_BUILD,
+            sha256 = bats_assert_sha256,
+            strip_prefix = "bats-assert-%s" % bats_assert_version,
+            urls = [
+                "https://github.com/bats-core/bats-assert/archive/refs/tags/v%s.tar.gz" % bats_assert_version,
+            ],
+        )
+    if bats_support_version:
+        if not bats_support_sha256:
+            fail("sha256 for bats-support was not supplied.")
+        http_archive(
+            name = "bats_support",
+            build_file_content = _BATS_SUPPORT_BUILD,
+            sha256 = bats_support_sha256,
+            strip_prefix = "bats-support-%s" % bats_support_version,
+            urls = [
+                "https://github.com/bats-core/bats-support/archive/refs/tags/v%s.tar.gz" % bats_support_version,
+            ],
+        )