Fix issue with jest not supporting symlinks

This adds jest.bzl and uses it to pass in specific tests.

See jestjs/jest#7549

jest.bzl

@@ -0,0 +1,29 @@
+load("@npm//jest-cli:index.bzl", "jest", _jest_test = "jest_test")
+
+def jest_test(name, srcs, deps, jest_config, **kwargs):
+    "A macro around the autogenerated jest_test rule"
+    templated_args = [
+        "--no-cache",
+        "--no-watchman",
+        "--ci",
+        "--colors",
+    ]
+    templated_args.extend(["--config", "$(rootpath %s)" % jest_config])
+    for src in srcs:
+        templated_args.extend(["--runTestsByPath", "$(rootpaths %s)" % src])
+
+    data = [jest_config] + srcs + deps
+    _jest_test(
+        name = name,
+        data = data,
+        templated_args = templated_args,
+        **kwargs
+    )
+
+    # This rule is used specifically to update snapshots via `bazel run`
+    jest(
+        name = "%s.update" % name,
+        data = data,
+        templated_args = templated_args + ["-u"],
+        **kwargs
+    )

jest.config.js

@@ -1,5 +1,4 @@
 module.exports = {
   reporters: ['default'],
   testEnvironment: 'node',
-  testMatch: ['**/*.test.js'],
 };

ts/lib/greet/BUILD.bazel

@@ -1,6 +1,6 @@
 load("@build_bazel_rules_nodejs//:index.bzl", "js_library")
 load("@npm//@bazel/typescript:index.bzl", "ts_config", "ts_project")
-load("@npm//jest-cli:index.bzl", "jest_test")
+load("//:jest.bzl", "jest_test")
 
 package(default_visibility = ["//visibility:public"])
 
@@ -28,18 +28,7 @@ js_library(
 
 jest_test(
     name = "ts_greet_test",
-    args = [
-        "--no-cache",
-        "--no-watchman",
-        "--ci",
-        "--colors",
-        "--config",
-        "jest.config.js",
-    ],
-    data = [
-        ":greet",
-        ":package.json",
-        ":tsconfig-greet",
-        "//:jest.config.js",
-    ],
+    srcs = [":tsconfig"],
+    jest_config = "//:jest.config.js",
+    deps = [],
 )