From 510514b64e642d34d05ba721dd190104238b57ab Mon Sep 17 00:00:00 2001
From: Kamil Samigullin <kamil@samigullin.info>
Date: Sun, 18 Apr 2021 23:18:03 +0300
Subject: [PATCH] issue #30: extend changelog by contribution diff command

---
 docs/changelog.md                    | 17 ++++++++++++++++-
 docs/readme.md                       | 19 +++++++++++++++++--
 internal/command/github/view/diff.go |  1 +
 3 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/docs/changelog.md b/docs/changelog.md
index 8b48ed6..8a7b762 100644
--- a/docs/changelog.md
+++ b/docs/changelog.md
@@ -58,7 +58,7 @@
     $ maintainer github contribution lookup /3         # -> now()/3 == now()/-1
     ```
 
-  * Makes a snapshot of contributions for a specified year
+  * Makes a snapshot of contributions for a specified year or shows changes
 
     ```bash
     $ maintainer github contribution snapshot 2013 | tee /tmp/snap.01.2013.json | jq
@@ -67,6 +67,21 @@
       ...
       "2013-12-27T00:00:00Z": 2
     }
+
+    $ maintainer github contribution diff --base=/tmp/snap.01.2013.json 2013
+     Day / Week                  #46             #48             #49           #50
+    ---------------------- --------------- --------------- --------------- -----------
+     Sunday                       -               -               -             -
+     Monday                       -               -               -             -
+     Tuesday                      -               -               -             -
+     Wednesday                   +4               -              +1             -
+     Thursday                     -               -               -            +1
+     Friday                       -              +2               -             -
+     Saturday                     -               -               -             -
+    ---------------------- --------------- --------------- --------------- -----------
+     The diff between head{"/tmp/snap.02.2013.json"} → base{"/tmp/snap.01.2013.json"}
+
+    $ maintainer github contribution diff --base=/tmp/snap.01.2013.json --head=/tmp/snap.02.2013.json
     ```
 
   * Suggests a reasonable date to contribute
diff --git a/docs/readme.md b/docs/readme.md
index bab2d35..038dbb6 100644
--- a/docs/readme.md
+++ b/docs/readme.md
@@ -58,15 +58,30 @@
     $ maintainer github contribution lookup /3         # -> now()/3 == now()/-1
     ```
 
-  * Makes a snapshot of contributions for a specified year
+  * Makes a snapshot of contributions for a specified year or shows changes
 
     ```bash
-    $ maintainer github contribution snapshot 2013 | tee snap.2013.json | jq
+    $ maintainer github contribution snapshot 2013 | tee /tmp/snap.01.2013.json | jq
     {
       "2013-11-13T00:00:00Z": 1,
       ...
       "2013-12-27T00:00:00Z": 2
     }
+
+    $ maintainer github contribution diff --base=/tmp/snap.01.2013.json 2013
+     Day / Week                  #46             #48             #49           #50
+    ---------------------- --------------- --------------- --------------- -----------
+     Sunday                       -               -               -             -
+     Monday                       -               -               -             -
+     Tuesday                      -               -               -             -
+     Wednesday                   +4               -              +1             -
+     Thursday                     -               -               -            +1
+     Friday                       -              +2               -             -
+     Saturday                     -               -               -             -
+    ---------------------- --------------- --------------- --------------- -----------
+     The diff between head{"/tmp/snap.02.2013.json"} → base{"/tmp/snap.01.2013.json"}
+
+    $ maintainer github contribution diff --base=/tmp/snap.01.2013.json --head=/tmp/snap.02.2013.json
     ```
 
   * Suggests a reasonable date to contribute
diff --git a/internal/command/github/view/diff.go b/internal/command/github/view/diff.go
index 8c19d61..b584cae 100644
--- a/internal/command/github/view/diff.go
+++ b/internal/command/github/view/diff.go
@@ -2,6 +2,7 @@ package view
 
 import (
 	"fmt"
+
 	"github.com/alexeyco/simpletable"
 
 	"go.octolab.org/toolset/maintainer/internal/model/github/contribution"