From 63f1a870558d692efb2964a975fa3c83b862f8a2 Mon Sep 17 00:00:00 2001
From: Austin Seipp <aseipp@pobox.com>
Date: Thu, 28 Mar 2024 15:45:31 -0500
Subject: [PATCH] cli: improve `snapshot.max-new-file-size` error message

For new users this results in a significantly better error output, that
actually shows them how to solve the problem, and why it happened.

Signed-off-by: Austin Seipp <aseipp@pobox.com>
Change-Id: Ide0c86fdfb40d66f970ceaef7b60a71392d2cd4b
---
 cli/src/command_error.rs       | 27 +++++++++++++++++++++------
 cli/tests/test_working_copy.rs | 11 ++++++++---
 2 files changed, 29 insertions(+), 9 deletions(-)

diff --git a/cli/src/command_error.rs b/cli/src/command_error.rs
index 4aa87af6a1..0c7a493588 100644
--- a/cli/src/command_error.rs
+++ b/cli/src/command_error.rs
@@ -295,12 +295,27 @@ impl From<OpsetEvaluationError> for CommandError {
 impl From<SnapshotError> for CommandError {
     fn from(err: SnapshotError) -> Self {
         match err {
-            SnapshotError::NewFileTooLarge { .. } => {
-                user_error_with_message("Failed to snapshot the working copy", err).hinted(
-                    r#"Increase the value of the `snapshot.max-new-file-size` config option if you
-want this file to be snapshotted. Otherwise add it to your `.gitignore` file."#,
-                )
-            }
+            SnapshotError::NewFileTooLarge {
+                path,
+                size,
+                max_size,
+            } => user_error(format!(
+                "Failed to snapshot the working copy\nThe file '{}' is too large to be \
+                 snapshotted ({} bytes).\nThe maximum size allowed is {} bytes.",
+                path.display(),
+                size.0,
+                max_size.0
+            ))
+            .hinted(format!(
+                "This is to prevent large files from being added on accident. You can fix this \
+                 error by:
+  - Adding the file to `.gitignore`
+  - Run `jj config set --repo snapshot.max-new-file-size \"{}B\"`
+    This will increase the maximum file size allowed for new files, in this repository only.
+  - Run `jj --config-toml 'snapshot.max-new-file-size=\"{}B\"' st`
+    This will increase the maximum file size allowed for new files, for this command only.",
+                size.0, size.0
+            )),
             err => internal_error_with_message("Failed to snapshot the working copy", err),
         }
     }
diff --git a/cli/tests/test_working_copy.rs b/cli/tests/test_working_copy.rs
index 461125b7f6..a7bacea343 100644
--- a/cli/tests/test_working_copy.rs
+++ b/cli/tests/test_working_copy.rs
@@ -25,8 +25,13 @@ fn test_snapshot_large_file() {
     let stderr = test_env.jj_cmd_failure(&repo_path, &["files"]);
     insta::assert_snapshot!(stderr, @r###"
     Error: Failed to snapshot the working copy
-    Caused by: New file $TEST_ENV/repo/large of size ~13.0B exceeds snapshot.max-new-file-size (10.0B)
-    Hint: Increase the value of the `snapshot.max-new-file-size` config option if you
-    want this file to be snapshotted. Otherwise add it to your `.gitignore` file.
+    The file '$TEST_ENV/repo/large' is too large to be snapshotted (13 bytes).
+    The maximum size allowed is 10 bytes.
+    Hint: This is to prevent large files from being added on accident. You can fix this error by:
+      - Adding the file to `.gitignore`
+      - Run `jj config set --repo snapshot.max-new-file-size "13B"`
+        This will increase the maximum file size allowed for new files, in this repository only.
+      - Run `jj --config-toml 'snapshot.max-new-file-size="13B"' st`
+        This will increase the maximum file size allowed for new files, for this command only.
     "###);
 }