diff --git a/__tests__/github.test.ts b/__tests__/github.test.ts
new file mode 100644
index 0000000..9259a16
--- /dev/null
+++ b/__tests__/github.test.ts
@@ -0,0 +1,92 @@
+const fakeContext = {
+  sha: "workflow-sha",
+  repo: {
+    owner: "owner",
+    repo: "repo",
+  },
+};
+describe("github", () => {
+  beforeEach(() => {
+    jest.resetModules();
+    jest.clearAllMocks();
+  });
+
+  it("creates GitHubContext from push event", () => {
+    jest.doMock("@actions/github", () => ({
+      context: {
+        ...fakeContext,
+        eventName: "push",
+      },
+    }));
+    const github = require("../src/github");
+
+    const result = github.getGitHubContext();
+    expect(result).toEqual({
+      owner: "owner",
+      repo: "repo",
+      sha: "workflow-sha",
+    });
+  });
+
+  it("creates GitHubContext from pull_request event", () => {
+    jest.doMock("@actions/github", () => ({
+      context: {
+        ...fakeContext,
+        eventName: "pull_request",
+        issue: { number: 42 },
+        payload: {
+          pull_request: {
+            head: { sha: "pr-sha" },
+          },
+        },
+      },
+    }));
+    const github = require("../src/github");
+
+    const result = github.getGitHubContext();
+    expect(result).toEqual({
+      owner: "owner",
+      repo: "repo",
+      sha: "pr-sha",
+      prNumber: 42,
+    });
+  });
+
+  it("creates GitHubContext from check_run event", () => {
+    jest.doMock("@actions/github", () => ({
+      context: {
+        ...fakeContext,
+        eventName: "check_run",
+        payload: {
+          check_run: {
+            pull_requests: [{ number: 42 }],
+            head_sha: "check-run-sha",
+          },
+        },
+      },
+    }));
+    const github = require("../src/github");
+
+    const result = github.getGitHubContext();
+    expect(result).toEqual({
+      owner: "owner",
+      repo: "repo",
+      sha: "check-run-sha",
+      prNumber: 42,
+    });
+  });
+
+  it("throws an error for unsupported event", () => {
+    jest.doMock("@actions/github", () => ({
+      context: {
+        ...fakeContext,
+        eventName: "unsupported",
+      },
+    }));
+    const github = require("../src/github");
+
+    expect(() => github.getGitHubContext()).toThrow(
+      "Unsupported event: unsupported",
+    );
+  });
+});
diff --git a/src/github.ts b/src/github.ts
index 339179c..a5d16a4 100644
--- a/src/github.ts
+++ b/src/github.ts
@@ -26,12 +26,13 @@ export interface PullRequestInfo {
  */
 export function getGitHubContext(): GitHubContext {
   const context = github.context;
-  const { eventName, sha } = context;
+  const { eventName } = context;
 
-  const commitInfo =
-    eventName !== "workflow_dispatch"
-      ? eventHandlers[eventName](context)
-      : { sha };
+  const handler = eventHandlers[eventName];
+  if (!handler) {
+    throw new Error(`Unsupported event: ${eventName}`);
+  }
+  const commitInfo = handler(context);
 
   return { ...getRepositoryInfo(), ...commitInfo };
 }
@@ -71,9 +72,15 @@ function getCheckRunContext(context: Context): PullRequestInfo {
   return { prNumber, sha };
 }
 
+function getShaFromContext(context: Context): PullRequestInfo {
+  return { sha: context.sha };
+}
+
 const eventHandlers: {
   [eventName: string]: (context: Context) => PullRequestInfo;
 } = {
   check_run: getCheckRunContext,
   pull_request: getPullRequestContext,
+  push: getShaFromContext,
+  workflow_dispatch: getShaFromContext,
 };