From f8fbe84817e95347061cf1dc3f900752329ce64e Mon Sep 17 00:00:00 2001
From: Andy Barron <andybarron@protonmail.com>
Date: Mon, 17 Jun 2024 17:05:21 -0700
Subject: [PATCH 1/2] add flag and fix existing tests

---
 source/types.ts                      | 2 ++
 source/utilities/cli.ts              | 4 ++++
 source/utilities/config.ts           | 7 +++++++
 tests/__snapshots__/cli.test.ts.snap | 2 ++
 4 files changed, 15 insertions(+)

diff --git a/source/types.ts b/source/types.ts
index 9294d7c3..13a1d913 100644
--- a/source/types.ts
+++ b/source/types.ts
@@ -79,6 +79,8 @@ export declare interface Options {
   '--no-clipboard': boolean;
   '--no-compression': boolean;
   '--no-etag': boolean;
+  '--trailing-slash': boolean;
+  '--no-trailing-slash': boolean;
   '--symlinks': boolean;
   '--cors': boolean;
   '--no-port-switching': boolean;
diff --git a/source/utilities/cli.ts b/source/utilities/cli.ts
index 726c5268..d9ae3750 100644
--- a/source/utilities/cli.ts
+++ b/source/utilities/cli.ts
@@ -54,6 +54,8 @@ const helpText = chalkTemplate`
 
     --no-etag                           Send \`Last-Modified\` header instead of \`ETag\`
 
+    --[no]-trailing-slash               Remove or add trailing slashes to all paths
+
     -S, --symlinks                      Resolve symlinks instead of showing 404 errors
     
     --ssl-cert                          Optional path to an SSL/TLS certificate to serve with HTTPS
@@ -153,6 +155,8 @@ const options = {
   '--no-clipboard': Boolean,
   '--no-compression': Boolean,
   '--no-etag': Boolean,
+  '--trailing-slash': Boolean,
+  '--no-trailing-slash': Boolean,
   '--symlinks': Boolean,
   '--cors': Boolean,
   '--no-port-switching': Boolean,
diff --git a/source/utilities/config.ts b/source/utilities/config.ts
index db2e3c85..d74a55ab 100644
--- a/source/utilities/config.ts
+++ b/source/utilities/config.ts
@@ -139,6 +139,13 @@ export const loadConfiguration = async (
   // Configure defaults based on the options the user has passed.
   config.etag = !args['--no-etag'];
   config.symlinks = args['--symlinks'] || config.symlinks;
+  const trailingSlash = args['--trailing-slash'];
+  const noTrailingSlash = args['--no-trailing-slash'];
+  if (trailingSlash !== undefined) {
+    config.trailingSlash = trailingSlash;
+  } else if (noTrailingSlash !== undefined) {
+    config.trailingSlash = !noTrailingSlash;
+  }
 
   return config;
 };
diff --git a/tests/__snapshots__/cli.test.ts.snap b/tests/__snapshots__/cli.test.ts.snap
index 87996f27..1b30bc85 100644
--- a/tests/__snapshots__/cli.test.ts.snap
+++ b/tests/__snapshots__/cli.test.ts.snap
@@ -43,6 +43,8 @@ exports[`utilities/cli > render help text 1`] = `
 
     --no-etag                           Send \`Last-Modified\` header instead of \`ETag\`
 
+    --[no]-trailing-slash               Remove or add trailing slashes to all paths
+
     -S, --symlinks                      Resolve symlinks instead of showing 404 errors
     
     --ssl-cert                          Optional path to an SSL/TLS certificate to serve with HTTPS

From 929af801a1a19004e557e207df48cbc017a9a2ff Mon Sep 17 00:00:00 2001
From: Andy Barron <andybarron@protonmail.com>
Date: Mon, 17 Jun 2024 17:23:01 -0700
Subject: [PATCH 2/2] add new tests

---
 tests/__fixtures__/config/custom/config.json |  1 +
 tests/__snapshots__/config.test.ts.snap      |  1 +
 tests/config.test.ts                         | 34 ++++++++++++++++++++
 3 files changed, 36 insertions(+)

diff --git a/tests/__fixtures__/config/custom/config.json b/tests/__fixtures__/config/custom/config.json
index 5df3e5ec..7a053db8 100644
--- a/tests/__fixtures__/config/custom/config.json
+++ b/tests/__fixtures__/config/custom/config.json
@@ -1,4 +1,5 @@
 {
   "public": "app/",
+  "trailingSlash": true,
   "renderSingle": true
 }
diff --git a/tests/__snapshots__/config.test.ts.snap b/tests/__snapshots__/config.test.ts.snap
index d1972f53..5a960d9a 100644
--- a/tests/__snapshots__/config.test.ts.snap
+++ b/tests/__snapshots__/config.test.ts.snap
@@ -15,6 +15,7 @@ exports[`utilities/config > parse valid config at custom location 1`] = `
   "public": "tests/__fixtures__/config/custom/app",
   "renderSingle": true,
   "symlinks": undefined,
+  "trailingSlash": true,
 }
 `;
 
diff --git a/tests/config.test.ts b/tests/config.test.ts
index 3240d1f0..31df145e 100644
--- a/tests/config.test.ts
+++ b/tests/config.test.ts
@@ -52,6 +52,40 @@ describe('utilities/config', () => {
     expect(configuration).toMatchSnapshot();
   });
 
+  // The `--trailing-slash` flag should set `trailingSlash` to `true`.
+  test('sets `trailingSlash` to `true` when --trailing-slash flag is set', async () => {
+    const configuration = await loadConfiguration(
+      process.cwd(),
+      process.cwd(),
+      {
+        '--trailing-slash': true,
+      },
+    );
+    expect(configuration.trailingSlash).toBe(true);
+  });
+
+  // The `--no-trailing-slash` flag should set `trailingSlash` to `false`.
+  test('sets `trailingSlash` to `false` when --no-trailing-slash flag is set', async () => {
+    const configuration = await loadConfiguration(
+      process.cwd(),
+      process.cwd(),
+      {
+        '--no-trailing-slash': true,
+      },
+    );
+    expect(configuration.trailingSlash).toBe(false);
+  });
+
+  // When `--[no]-trailing-slash` is not specified, `trailingSlash` should be `undefined`.
+  test('sets `trailingSlash` to `undefined` when trailing slash flags are omitted', async () => {
+    const configuration = await loadConfiguration(
+      process.cwd(),
+      process.cwd(),
+      {},
+    );
+    expect(configuration.trailingSlash).toBeUndefined();
+  });
+
   // When the configuration source is deprecated, i.e., the configuration lives
   // in `now.json` or `package.json`, a warning should be printed.
   test('warn when configuration comes from a deprecated source', async () => {