Update tutorial for 0.23 and clarify diffedit

docs/tutorial.md

@@ -1,8 +1,8 @@
 # Tutorial
 
->  **Hint:** This tutorial has become somewhat out of date. Many people find
->   the alternative (not quite finished) [tutorial by Steve
->   Klabnik](https://steveklabnik.github.io/jujutsu-tutorial/) helpful.
+> **Hint:** This tutorial has become somewhat out of date. Many people find
+> the alternative (not quite finished) [tutorial by Steve
+> Klabnik](https://steveklabnik.github.io/jujutsu-tutorial/) helpful.
 
 This text assumes that the reader is familiar with Git.
 
@@ -11,7 +11,10 @@ This text assumes that the reader is familiar with Git.
 If you haven't already, make sure you
 [install and configure Jujutsu](install-and-setup.md).
 
-## Cloning a Git repo
+## Cloning a Git repository
+
+> **Hint:** Most identifiers used in this tutorial will be different when you
+> try this at home!
 
 Let's start by cloning GitHub's Hello-World repo using `jj`:
 
@@ -20,6 +23,10 @@ Let's start by cloning GitHub's Hello-World repo using `jj`:
 # repos yet)
 $ jj git clone https://github.com/octocat/Hello-World
 Fetching into new repo in "/tmp/tmp.O1DWMiaKd4/Hello-World"
+bookmark: master@origin          [new] untracked
+bookmark: octocat-patch-1@origin [new] untracked
+bookmark: test@origin            [new] untracked
+Setting the revset alias "trunk()" to "master@origin"
 Working copy now at: kntqzsqt d7439b06 (empty) (no description set)
 Parent commit      : orrkosyo 7fd1a60b master | (empty) Merge pull request #6 from Spaceghost/patch-1
 Added 1 files, modified 0 files, removed 0 files
@@ -35,20 +42,55 @@ Working copy : kntqzsqt d7439b06 (empty) (no description set)
 Parent commit: orrkosyo 7fd1a60b master | (empty) Merge pull request #6 from Spaceghost/patch-1
 ```
 
-We can see from the output above that our working copy is a real commit with a
+Let's look at that output as it introduces new concepts.
+You can see two commits: Parent and working copy.
+Both are identified using two separate identifiers: the "change ID" and the
+"commit ID".
+
+The parent commit, for example, has the change ID `orrkosyo` and the
+commit ID `7fd1a60b`.
+
+> **Git users:** The commit ID/hash is what you're used to from Git and should
+> match what you see when you look at the repository using `git log` in a Git
+> checkout of the repository.
+> The change ID however, is a new concept, unique to Jujutsu.
+
+We can also see from the output above that our working copy is an actual commit
+with a
 commit ID (`d7439b06` in the example). When you make a change in the working
 copy, the working-copy commit gets automatically amended by the next `jj`
 command.
 
+> **Git users:** This is a huge difference from Git where the working copy is a
+> separate concept
+> and not yet a commit.
+
+## Changes
+
+A change is a commit that can evolve while keeping a stable identifier (similar
+to Gerrit's Change-Id).
+In other words: You can make changes to files in a change, resulting in a new
+commit hash, but the change ID will remain the same.
+
+You can see that our clone operation automatically created a new change:
+
+```
+Working copy : kntqzsqt d7439b06 (empty) (no description set)
+```
+
+This new change has the ID `kntqzsqt` and it is currently empty (contains no
+changes compared to the parent) and has no description.
+
 ## Creating our first change
 
-Now let's say we want to edit the `README` file in the repo to say "Goodbye"
-instead of "Hello". Let's start by describing the change (adding a
-commit message) so we don't forget what we're working on:
+Let's say we want to edit the `README` file in the repo to say "Goodbye"
+instead of "Hello".
+Start by describing the change (adding a commit message) so we don't forget what
+we're working on:
 
 ```shell
-# This will bring up $EDITOR (or `pico` or `Notepad` by default). Enter
-# something like "Say goodbye" in the editor and then save the file and close
+# This brings up $EDITOR (or `pico` or `Notepad` by default).
+# Enter something like "Say goodbye" in the editor and then save the file and close
 # the editor.
 $ jj describe
 Working copy now at: kntqzsqt e427edcf (empty) Say goodbye
@@ -72,6 +114,9 @@ Note that you didn't have to tell Jujutsu to add the change like you would with
 remove existing files. To untrack a path, add it to your `.gitignore` and run
 `jj file untrack <path>`.
 
+Also note that the commit hash for our current change (`kntqzsqt`) changed from
+`e427edcf` to `5d39e19d`!
+
 To see the diff, run `jj diff`:
 
 ```shell
@@ -110,11 +155,12 @@ Parent commit: kntqzsqt 5d39e19d Say goodbye
 ```
 
 If we later realize that we want to make further changes, we can make them
-in the working copy and then run `jj squash`. That command squashes the changes
-from a given commit into its parent commit. Like most commands, it acts on the
-working-copy commit by default. When run on the working-copy commit, it behaves
-very similar to `git commit --amend`, and `jj amend` is in fact an alias for
-`jj squash`.
+in the working copy and then run `jj squash`.
+That command squashes (moves) the changes from a given commit into its
+parent commit.
+Like most commands, it acts on the working-copy commit by default.
+When run on the working-copy commit, it behaves very similar to
+`git commit --amend`, and `jj amend` is in fact an alias for `jj squash`.
 
 Alternatively, we can use `jj edit <commit>` to resume editing a commit in the
 working copy. Any further changes in the working copy will then amend the
@@ -124,8 +170,8 @@ done, it makes sense to use `jj new` so you can easily review your adjustments
 with `jj diff` before running `jj squash`.
 
 To view how a change has evolved over time, we can use `jj evolog` to see each
-recorded change for the current commit. This records changes to the working copy,
-message, squashes, rebases, etc.
+recorded change for the current commit.
+This records changes to the working copy, message, squashes, rebases, etc.
 
 ## The log command and "revsets"
 
@@ -148,14 +194,14 @@ $ jj log
 ```
 
 The `@` indicates the working-copy commit. The first ID on a line
-(e.g. "mpqrykyp" above) is the "change ID", which is an ID that follows the
-commit as it's rewritten (similar to Gerrit's Change-Id). The second ID is the
-commit ID, which changes when you rewrite the commit. You can give either ID
-to commands that take revisions as arguments. We will generally prefer change
-IDs because they stay the same when the commit is rewritten.
+(e.g. "mpqrykyp" above) is the change ID.
+The second ID is the commit ID.
+You can give either ID to commands that take revisions as arguments.
+We will generally prefer change IDs because they stay the same when
+the commit is rewritten.
 
 By default, `jj log` lists your local commits, with some remote commits added
-for context.  The `~` indicates that the commit has parents that are not
+for context. The `~` indicates that the commit has parents that are not
 included in the graph. We can use the `--revisions`/`-r` flag to select a
 different set of revisions to list. The flag accepts a ["revset"](revsets.md),
 which is an expression in a simple language for specifying revisions. For
@@ -235,6 +281,11 @@ on A.
 ```shell
 $ jj rebase -s puqltutt -d nuvyytnq  # Replace the IDs by what you have for B2 and A
 Rebased 2 commits
+Working copy now at: qzvqqupx 1978b534 (conflict) C
+Parent commit      : puqltutt f7fb5943 (conflict) B2
+Added 0 files, modified 1 files, removed 0 files
+There are unresolved conflicts at these paths:
+file1    2-sided conflict
 New conflicts appeared in these commits:
   qzvqqupx 1978b534 (conflict) C
   puqltutt f7fb5943 (conflict) B2
@@ -243,9 +294,7 @@ To resolve the conflicts, start by updating to the first one:
 Then use `jj resolve`, or edit the conflict markers in the file directly.
 Once the conflicts are resolved, you may want to inspect the result with `jj diff`.
 Then run `jj squash` to move the resolution into the conflicted commit.
-Working copy now at: qzvqqupx 1978b534 (conflict) C
-Parent commit      : puqltutt f7fb5943 (conflict) B2
-Added 0 files, modified 1 files, removed 0 files
+
 $ jj log
 @  qzvqqupx [email protected] 2023-02-12 15:08:33.000 -08:00 1978b534 conflict
 │  C
@@ -283,28 +332,44 @@ $ jj new puqltutt  # Replace the ID by what you have for B2
 Working copy now at: zxoosnnp c7068d1c (conflict) (empty) (no description set)
 Parent commit      : puqltutt f7fb5943 (conflict) B2
 Added 0 files, modified 0 files, removed 1 files
+There are unresolved conflicts at these paths:
+file1    2-sided conflict
+
 $ jj st
 The working copy is clean
 There are unresolved conflicts at these paths:
 file1    2-sided conflict
 Working copy : zxoosnnp c7068d1c (conflict) (empty) (no description set)
 Parent commit: puqltutt f7fb5943 (conflict) B2
+To resolve the conflicts, start by updating to it:
+  jj new puqltutt
+Then use `jj resolve`, or edit the conflict markers in the file directly.
+Once the conflicts are resolved, you may want to inspect the result with `jj diff`.
+Then run `jj squash` to move the resolution into the conflicted commit.
+
 $ cat file1
-<<<<<<<
-%%%%%%%
--b1
-+a
-+++++++
-b2
->>>>>>>
+<<<<<<< Conflict 1 of 1
+%%%%%%% Changes from base to side #1
+-b1+a+++++++ Contents of side #2
+b2>>>>>>> Conflict 1 of 1 ends
+
 $ echo resolved > file1
+
+$ jj st
+Working copy changes:
+M file1
+Working copy : zxoosnnp c2a31a06 (no description set)
+Parent commit: puqltutt f7fb5943 (conflict) B2
+Conflict in parent commit has been resolved in working copy
+
 $ jj squash
 Rebased 1 descendant commits
+Working copy now at: ntxxqymr e3c279cc (empty) (no description set)
+Parent commit      : puqltutt 2c7a658e B2
 Existing conflicts were resolved or abandoned from these commits:
   qzvqqupx hidden 1978b534 (conflict) C
   puqltutt hidden f7fb5943 (conflict) B2
-Working copy now at: ntxxqymr e3c279cc (empty) (no description set)
-Parent commit      : puqltutt 2c7a658e B2
+
 $ jj log
 @  ntxxqymr [email protected] 2023-02-12 19:34:09.000 -08:00 e3c279cc
 │  (empty) (no description set)
@@ -372,6 +437,7 @@ Once the conflicts are resolved, you may want to inspect the result with `jj dif
 Then run `jj squash` to move the resolution into the conflicted commit.
 Working copy now at: zxoosnnp 63874fe6 (no description set)
 Parent commit      : puqltutt f7fb5943 (conflict) B2
+
 $ jj log
 @  zxoosnnp [email protected] 2023-02-12 19:34:09.000 -08:00 63874fe6
 │  (no description set)
@@ -399,7 +465,8 @@ squashing the conflict resolution into commit B2 earlier. Notice that it also
 updated the working copy.
 
 You can also view the repo the way it looked after some earlier operation. For
-example, if you want to see `jj log` output right after the `jj rebase` operation,
+example, if you want to see `jj log` output right after the `jj rebase`
+operation,
 try `jj log --at-op=367400773f87` but use the hash from your own `jj op log`.
 
 ## Moving content changes between commits
@@ -416,12 +483,15 @@ $ jj new master -m abc; printf 'a\nb\nc\n' > file
 Working copy now at: ztqrpvnw f94e49cf (empty) abc
 Parent commit      : orrkosyo 7fd1a60b master | (empty) Merge pull request #6 from Spaceghost/patch-1
 Added 0 files, modified 0 files, removed 1 files
+
 $ jj new -m ABC; printf 'A\nB\nc\n' > file
 Working copy now at: kwtuwqnm 6f30cd1f (empty) ABC
 Parent commit      : ztqrpvnw 51002261 ab
+
 $ jj new -m ABCD; printf 'A\nB\nC\nD\n' > file
 Working copy now at: mrxqplyk a6749154 (empty) ABCD
 Parent commit      : kwtuwqnm 30aecc08 ABC
+
 $ jj log -r master::@
 @  mrxqplyk [email protected] 2023-02-12 19:38:21.000 -08:00 b98c607b
 │  ABCD
@@ -444,7 +514,8 @@ Now try that:
 
 ```shell
 $ jj squash -i
-Using default editor ':builtin'; you can change this by setting ui.diff-editor
+Hint: Using default editor ':builtin'; run `jj config set --user ui.diff-editor :builtin` to disable this message.
+Rebased 1 descendant commits
 Working copy now at: mrxqplyk 52a6c7fd ABCD
 Parent commit      : kwtuwqnm 643061ac ABC
 ```
@@ -467,11 +538,18 @@ If we look at the diff of the second commit, we now see
 that all three lines got capitalized:
 
 ```shell
-$ jj diff -r @-
-Modified regular file file:
-   1    1: aA
-   2    2: bB
-   3    3: cC
+$ jj diff -r @- --git
+diff --git a/file b/file
+index de980441c3..b1e67221af 100644
+--- a/file
++++ b/file
+@@ -1,3 +1,3 @@
+-a
+-b
+-c
++A
++B
++C
 ```
 
 The child change ("ABCD" in our case) will have the same content *state* after
@@ -481,32 +559,38 @@ conflicts.
 
 Let's try one final command for changing the contents of an exiting commit. That
 command is `jj diffedit`, which lets you edit the contents of a commit without
-checking it out.
+checking it out (i.e. the "right side").
 
 ```shell
 $ jj diffedit -r @-
-Using default editor ':builtin'; you can change this by setting ui.diff-editor
+Hint: Using default editor ':builtin'; run `jj config set --user ui.diff-editor :builtin` to disable this message.
 Created kwtuwqnm 70985eaa (empty) ABC
 Rebased 1 descendant commits
+Working copy now at: mrxqplyk 1c72cd50 (conflict) ABCD
+Parent commit      : kwtuwqnm 70985eaa (empty) ABC
+Added 0 files, modified 1 files, removed 0 files
+There are unresolved conflicts at these paths:
+file    2-sided conflict
 New conflicts appeared in these commits:
   mrxqplyk 1c72cd50 (conflict) ABCD
 To resolve the conflicts, start by updating to it:
   jj new mrxqplykmyqv
 Then use `jj resolve`, or edit the conflict markers in the file directly.
 Once the conflicts are resolved, you may want to inspect the result with `jj diff`.
 Then run `jj squash` to move the resolution into the conflicted commit.
-Working copy now at: mrxqplyk 1c72cd50 (conflict) ABCD
-Parent commit      : kwtuwqnm 70985eaa (empty) ABC
-Added 0 files, modified 1 files, removed 0 files
 ```
 
-In the diff editor, edit the right side by e.g. adding something to the first
-line. Press 'c' to save the changes and close it. You can now inspect the rewritten
-commit with `jj diff -r @-` again and you should see your addition to the first
-line. Unlike `jj squash -i`, which left the content state of the commit
-unchanged, `jj diffedit` (typically) results in a different state, which means
+In this case the default diff editor is not powerful enough to allow you to
+actually do much other than picking hunks from the existing diff.
+Using an alternative diff editor as described above you can change the commit
+entirely and add or delete content as you wish.
+You can now inspect the rewritten commit with `jj diff -r @-` again, and you
+should see your addition to the first line.
+Unlike `jj squash -i`, which left the content state of the commit unchanged,
+`jj diffedit` (typically) results in a different state, which means
 that descendant commits may have conflicts.
 
-Another command for rewriting contents of existing commits is `jj split`. Now that
-you've seen how `jj squash -i` and `jj diffedit` work, you can hopefully figure out
-how it works (with the help of the instructions in the diff).
+Another command for rewriting contents of existing commits is `jj split`.
+Now that you've seen how `jj squash -i` and `jj diffedit` work, you can
+hopefully figure out how it works (with the help of the instructions in the
+diff).