feat: support SKIP_INSTALL_SIMPLE_GIT_HOOKS env (#107)

ta da! Thanks @JounQin 

Will release a new version today || tomorrow

Author: JounQin

README.md

@@ -162,7 +162,15 @@ npm uninstall simple-git-hooks
 
 ### I want to skip git hooks!
 
-You should use `--no-verify` option
+If you need to bypass install hooks at all, for example on CI, you can use `SKIP_INSTALL_SIMPLE_GIT_HOOKS` environment variable at the first place.
+
+```sh
+export SKIP_INSTALL_SIMPLE_GIT_HOOKS=1
+
+npm install simple-git-hooks --save-dev
+```
+
+Or if you only need to bypass hooks for a single git operation, you should use `--no-verify` option
 
 ```sh
 git commit -m "commit message" --no-verify # -n for shorthand

cli.js

@@ -6,6 +6,13 @@
  */
 const {setHooksFromConfig} = require('./simple-git-hooks')
 
+const {SKIP_INSTALL_SIMPLE_GIT_HOOKS} = process.env
+
+if (['1', 'true'].includes(SKIP_INSTALL_SIMPLE_GIT_HOOKS)) {
+    console.log(`[INFO] SKIP_INSTALL_SIMPLE_GIT_HOOKS is set to "${SKIP_INSTALL_SIMPLE_GIT_HOOKS}", skipping installing hook.`)
+    return
+}
+
 try {
     setHooksFromConfig(process.cwd(), process.argv)
     console.log('[INFO] Successfully set all git hooks')

simple-git-hooks.test.js

@@ -449,6 +449,59 @@ describe("Simple Git Hooks tests", () => {
           expect(isEqual(installedHooks, COMMON_GIT_HOOKS)).toBe(true);
         });
       });
+
+      describe("SKIP_INSTALL_SIMPLE_GIT_HOOKS", () => {
+        afterEach(() => {
+            removeGitHooksFolder(PROJECT_WITH_CONF_IN_PACKAGE_JSON);
+        });
+
+        it("does not create git hooks when SKIP_INSTALL_SIMPLE_GIT_HOOKS is set to 1", () => {
+          createGitHooksFolder(PROJECT_WITH_CONF_IN_PACKAGE_JSON);
+          execSync(`node ${require.resolve("./cli")}`, {
+            cwd: PROJECT_WITH_CONF_IN_PACKAGE_JSON,
+            env: {
+                ...process.env,
+                SKIP_INSTALL_SIMPLE_GIT_HOOKS: "1",
+            },
+          });
+          const installedHooks = getInstalledGitHooks(
+              path.normalize(
+                  path.join(PROJECT_WITH_CONF_IN_PACKAGE_JSON, ".git", "hooks")
+              )
+          );
+          expect(installedHooks).toEqual({});
+        });
+
+        it("creates git hooks when SKIP_INSTALL_SIMPLE_GIT_HOOKS is set to 0", () => {
+          createGitHooksFolder(PROJECT_WITH_CONF_IN_PACKAGE_JSON);
+          execSync(`node ${require.resolve("./cli")}`, {
+            cwd: PROJECT_WITH_CONF_IN_PACKAGE_JSON,
+            env: {
+                ...process.env,
+                SKIP_INSTALL_SIMPLE_GIT_HOOKS: "0",
+            },
+          });
+          const installedHooks = getInstalledGitHooks(
+              path.normalize(
+                  path.join(PROJECT_WITH_CONF_IN_PACKAGE_JSON, ".git", "hooks")
+              )
+          );
+          expect(installedHooks).toEqual({ "pre-commit": TEST_SCRIPT });
+        });
+
+        it("creates git hooks when SKIP_INSTALL_SIMPLE_GIT_HOOKS is not set", () => {
+          createGitHooksFolder(PROJECT_WITH_CONF_IN_PACKAGE_JSON);
+          execSync(`node ${require.resolve("./cli")}`, {
+            cwd: PROJECT_WITH_CONF_IN_PACKAGE_JSON,
+          });
+          const installedHooks = getInstalledGitHooks(
+              path.normalize(
+                  path.join(PROJECT_WITH_CONF_IN_PACKAGE_JSON, ".git", "hooks")
+              )
+          );
+          expect(installedHooks).toEqual({ "pre-commit": TEST_SCRIPT });
+        });
+      });
     });
 
     describe("ENV vars features tests", () => {