From 6b8069b823103b82073967f7835e4d6efb8d0f0a Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Wed, 11 Aug 2021 19:35:28 +0200
Subject: [PATCH 1/2] In flake lock file diffs, show the last-modified date of
 inputs if available

This is a bit more informative than just the hash.

Also, format the diffs a bit nicer.
---
 src/libexpr/flake/flake.cc    |  4 ++--
 src/libexpr/flake/lockfile.cc | 21 +++++++++++++++++----
 2 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/src/libexpr/flake/flake.cc b/src/libexpr/flake/flake.cc
index e7013b241..a2f100cbd 100644
--- a/src/libexpr/flake/flake.cc
+++ b/src/libexpr/flake/flake.cc
@@ -567,8 +567,8 @@ LockedFlake lockFlake(
                         topRef.input.markChangedFile(
                             (topRef.subdir == "" ? "" : topRef.subdir + "/") + "flake.lock",
                             lockFlags.commitLockFile
-                            ? std::optional<std::string>(fmt("%s: %s\n\nFlake input changes:\n\n%s",
-                                    relPath, lockFileExists ? "Update" : "Add", diff))
+                            ? std::optional<std::string>(fmt("%s: %s\n\nFlake lock file changes:\n\n%s",
+                                    relPath, lockFileExists ? "Update" : "Add", filterANSIEscapes(diff, true)))
                             : std::nullopt);
 
                         /* Rewriting the lockfile changed the top-level
diff --git a/src/libexpr/flake/lockfile.cc b/src/libexpr/flake/lockfile.cc
index 6089d1363..fda340789 100644
--- a/src/libexpr/flake/lockfile.cc
+++ b/src/libexpr/flake/lockfile.cc
@@ -2,6 +2,8 @@
 #include "store-api.hh"
 #include "url-parts.hh"
 
+#include <iomanip>
+
 #include <nlohmann/json.hpp>
 
 namespace nix::flake {
@@ -268,10 +270,20 @@ std::map<InputPath, Node::Edge> LockFile::getAllInputs() const
     return res;
 }
 
+static std::string describe(const FlakeRef & flakeRef)
+{
+    auto s = fmt("'%s'", flakeRef.to_string());
+
+    if (auto lastModified = flakeRef.input.getLastModified())
+        s += fmt(" (%s)", std::put_time(std::gmtime(&*lastModified), "%Y-%m-%d"));
+
+    return s;
+}
+
 std::ostream & operator <<(std::ostream & stream, const Node::Edge & edge)
 {
     if (auto node = std::get_if<0>(&edge))
-        stream << "'" << (*node)->lockedRef << "'";
+        stream << describe((*node)->lockedRef);
     else if (auto follows = std::get_if<1>(&edge))
         stream << fmt("follows '%s'", printInputPath(*follows));
     return stream;
@@ -299,14 +311,15 @@ std::string LockFile::diff(const LockFile & oldLocks, const LockFile & newLocks)
 
     while (i != oldFlat.end() || j != newFlat.end()) {
         if (j != newFlat.end() && (i == oldFlat.end() || i->first > j->first)) {
-            res += fmt("* Added '%s': %s\n", printInputPath(j->first), j->second);
+            res += fmt("• " ANSI_GREEN "Added input '%s':" ANSI_NORMAL "\n    %s\n",
+                printInputPath(j->first), j->second);
             ++j;
         } else if (i != oldFlat.end() && (j == newFlat.end() || i->first < j->first)) {
-            res += fmt("* Removed '%s'\n", printInputPath(i->first));
+            res += fmt("• " ANSI_RED "Removed input '%s'" ANSI_NORMAL "\n", printInputPath(i->first));
             ++i;
         } else {
             if (!equals(i->second, j->second)) {
-                res += fmt("* Updated '%s': %s -> %s\n",
+                res += fmt("• " ANSI_BOLD "Updated input '%s':" ANSI_NORMAL "\n    %s\n  → %s\n",
                     printInputPath(i->first),
                     i->second,
                     j->second);

From 3af1c28ebbf6270319551eb8468aa1a715fc7063 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Wed, 11 Aug 2021 19:36:34 +0200
Subject: [PATCH 2/2] flake.lock: Update
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Flake lock file changes:

• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/f77036342e2b690c61c97202bf48f2ce13acc022' (2021-06-28)
  → 'github:NixOS/nixpkgs/f6551e1efa261568c82b76c3a582b2c2ceb1f53f' (2021-08-11)
---
 flake.lock | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/flake.lock b/flake.lock
index 5fc969d7b..8c0d5a2d2 100644
--- a/flake.lock
+++ b/flake.lock
@@ -19,11 +19,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1624862269,
-        "narHash": "sha256-JFcsh2+7QtfKdJFoPibLFPLgIW6Ycnv8Bts9a7RYme0=",
+        "lastModified": 1628689438,
+        "narHash": "sha256-YMINW6YmubHZVdliGsAJpnnMYXRrvppv59LgwtnyYhs=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "f77036342e2b690c61c97202bf48f2ce13acc022",
+        "rev": "f6551e1efa261568c82b76c3a582b2c2ceb1f53f",
         "type": "github"
       },
       "original": {