Add a script for re-recording every demo a page embeds

Changing demo/settings.tape, or anything about how lazygit looks, dates
every recording at once, and re-recording them one at a time means
running the recorder fifteen times and pasting fifteen new URLs.
Attachment URLs say nothing about where they came from, so there is also
nothing to tell you which demo a video in the README is of.

Name the demo in a comment above each video. GitHub drops the comment
when it renders the page, so it costs the reader nothing, and it gives
us a way back from a page to the demo that produced it. Then walk those
comments, re-record each demo and rewrite the URL below it.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Makefile

@@ -68,6 +68,10 @@ bump-lazycore:
 record-demo:
 	demo/record_demo.sh $(filter-out $@,$(MAKECMDGOALS))
 
+.PHONY: rerecord-demos
+rerecord-demos:
+	demo/rerecord_demos.sh $(filter-out $@,$(MAKECMDGOALS))
+
 .PHONY: vendor
 vendor:
 	go mod tidy && go mod vendor

demo/rerecord_demos.sh

@@ -0,0 +1,113 @@
+#!/bin/sh
+
+set -e
+
+# Re-records the demos that a page embeds and points the page at the new
+# videos. Use it when a change to demo/settings.tape, or to lazygit's
+# appearance, leaves the existing recordings looking out of date.
+#
+# A page names the demo behind each video in a comment above it:
+#
+#   <!-- demo: commit_and_push -->
+#   <video src="https://github.com/user-attachments/assets/..." controls></video>
+#
+# GitHub drops that comment when it renders the page, so it costs the reader
+# nothing. This script re-records the demo the comment names and rewrites the
+# URL on the line below it.
+
+usage() {
+    echo "Usage: $0 [--no-upload] [page ...]"
+    echo "e.g. $0 README.md"
+    echo
+    echo "Re-records every demo the given pages embed. With no page given,"
+    echo "that means README.md."
+    echo
+    echo "--no-upload leaves the videos in demo/output and the pages untouched,"
+    echo "which is what you want for reviewing a change to demo/settings.tape."
+    exit 1
+}
+
+NO_UPLOAD=
+
+if [ "$1" = "--no-upload" ]
+then
+    NO_UPLOAD=--no-upload
+    shift
+fi
+
+if [ "$1" = "-h" ] || [ "$1" = "--help" ]
+then
+    usage
+fi
+
+if [ ! -x demo/record_demo.sh ]
+then
+    echo "Run this from the root of the repository."
+    exit 1
+fi
+
+if [ "$#" -eq 0 ]
+then
+    set -- README.md
+fi
+
+for PAGE in "$@"
+do
+    if [ ! -f "$PAGE" ]
+    then
+        echo "$PAGE does not exist"
+        exit 1
+    fi
+
+    NAMES=$(sed -n 's/^<!-- demo: \([A-Za-z0-9_]*\) -->$/\1/p' "$PAGE")
+
+    if [ -z "$NAMES" ]
+    then
+        echo "$PAGE embeds no demos. Each video needs a <!-- demo: <name> -->"
+        echo "comment on the line above it to say which demo it came from."
+        exit 1
+    fi
+
+    for NAME in $NAMES
+    do
+        TEST="pkg/integration/tests/demo/$NAME.go"
+
+        if [ ! -f "$TEST" ]
+        then
+            echo "$PAGE asks for a demo called $NAME, but $TEST does not exist"
+            exit 1
+        fi
+
+        echo
+        echo "=== $NAME ==="
+
+        if [ -n "$NO_UPLOAD" ]
+        then
+            demo/record_demo.sh --no-upload "$TEST"
+            continue
+        fi
+
+        # Keep the recording chatter on screen, since a full run takes a while,
+        # and read the new URL back out of it afterwards.
+        LOG=$(mktemp)
+        demo/record_demo.sh "$TEST" | tee "$LOG"
+        URL=$(sed -n 's/.*<video src="\([^"]*\)".*/\1/p' "$LOG")
+        rm -f "$LOG"
+
+        if [ -z "$URL" ]
+        then
+            echo "Recording $NAME produced no URL"
+            exit 1
+        fi
+
+        awk -v marker="<!-- demo: $NAME -->" -v url="$URL" '
+            hit { sub(/src="[^"]*"/, "src=\"" url "\""); hit = 0 }
+            $0 == marker { hit = 1 }
+            { print }
+        ' "$PAGE" > "$PAGE.new"
+
+        mv "$PAGE.new" "$PAGE"
+
+        echo "$PAGE now points at $URL"
+    done
+done

docs-master/dev/Demo_Recordings.md

@@ -106,3 +106,26 @@ every recording.
 
 Uploading needs push access to the lazygit repository. If you don't have it,
 record the demo, then ask a maintainer to upload the mp4 for you.
+
+### Re-recording every demo on a page
+
+Write the name of the demo above each video, so that we can find our way from
+a page back to the demo that produced it:
+
+```html
+<!-- demo: commit_and_push -->
+<video src="https://github.com/user-attachments/assets/<uuid>" controls></video>
+```
+
+GitHub drops the comment when it renders the page. With it in place, a change
+to `demo/settings.tape` or to lazygit's own appearance can be rolled out across
+every recording at once:
+
+```sh
+scripts/rerecord_demos.sh
+# or, to look before you upload anything:
+scripts/rerecord_demos.sh --no-upload
+```
+
+That re-records every demo the README embeds and rewrites each URL in place.
+Name other pages as arguments to do the same for them.

justfile

@@ -74,5 +74,9 @@ bump-gocui:
 demo *args:
     demo/record_demo.sh {{ args }}
 
+# Re-record every demo the README embeds
+rerecord-demos *args:
+    demo/rerecord_demos.sh {{ args }}
+
 vendor:
     go mod tidy && go mod vendor

scripts/rerecord_demos.sh

@@ -0,0 +1,3 @@
+#!/bin/sh
+
+demo/rerecord_demos.sh "$@"