From feb8cdf9e8e0c1b5d76253cc855aea26233b4dd5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Michal=20=C4=8Ciha=C5=99?= <michal@cihar.com>
Date: Fri, 19 Jul 2024 14:28:53 +0200
Subject: [PATCH] Add support to change lint output format from environment

Use REUSE_OUTPUT_FORMAT to allow overriding lint output formats in certain
environments (like CI).
---
 changelog.d/added/format-env.md |  2 ++
 docs/man/reuse-lint.rst         |  9 +++++++++
 src/reuse/lint.py               | 32 ++++++++++++++++++++++----------
 3 files changed, 33 insertions(+), 10 deletions(-)
 create mode 100644 changelog.d/added/format-env.md

diff --git a/changelog.d/added/format-env.md b/changelog.d/added/format-env.md
new file mode 100644
index 00000000..3ee98ce4
--- /dev/null
+++ b/changelog.d/added/format-env.md
@@ -0,0 +1,2 @@
+- Added `REUSE_OUTPUT_FORMAT` environment variable to configure output for
+  `lint`.
diff --git a/docs/man/reuse-lint.rst b/docs/man/reuse-lint.rst
index 2a086a87..a750185e 100644
--- a/docs/man/reuse-lint.rst
+++ b/docs/man/reuse-lint.rst
@@ -103,3 +103,12 @@ Options
 .. option:: -h, --help
 
   Display help and exit.
+
+Environment
+-----------
+
+.. envvar:: REUSE_OUTPUT_FORMAT
+
+   Specifies output format, one of ``plain``, ``lines``, ``github``, ``json``
+
+   It behaves same as corresponding command line options.
diff --git a/src/reuse/lint.py b/src/reuse/lint.py
index 87e4a440..36427a80 100644
--- a/src/reuse/lint.py
+++ b/src/reuse/lint.py
@@ -11,6 +11,7 @@
 """
 
 import json
+import os
 import sys
 from argparse import ArgumentParser, Namespace
 from gettext import gettext as _
@@ -374,15 +375,26 @@ def run(args: Namespace, project: Project, out: IO[str] = sys.stdout) -> int:
         project, do_checksum=False, multiprocessing=not args.no_multiprocessing
     )
 
-    if args.quiet:
-        pass
-    elif args.json:
-        out.write(format_json(report))
-    elif args.lines:
-        out.write(format_lines(report))
-    elif args.github:
-        out.write(format_github(report))
-    else:
-        out.write(format_plain(report))
+    formatters = {
+        "json": format_json,
+        "lines": format_lines,
+        "github": format_github,
+        "plain": format_plain,
+    }
+
+    if not args.quiet:
+        output_format = os.environ.get("REUSE_OUTPUT_FORMAT")
+
+        if output_format is not None and output_format in formatters:
+            formatter = formatters[output_format]
+            out.write(formatter(report))
+        elif args.json:
+            out.write(format_json(report))
+        elif args.lines:
+            out.write(format_lines(report))
+        elif args.github:
+            out.write(format_github(report))
+        else:
+            out.write(format_plain(report))
 
     return 0 if report.is_compliant else 1