Add tests for the show_commit module

Also fix a few bugs and inconsistencies in the rendering found while
writing the tests.

6 files changed, 1336 insertions, 35 deletions

diff --git a/src/show_commit/commit.rs b/src/show_commit/commit.rs
index 39f18ad..10191a3 100644
--- a/src/show_commit/commit.rs
+++ b/src/show_commit/commit.rs
@@ -23,15 +23,15 @@ pub(super) struct LoadCommitDiffOptions {
 
 #[derive(Debug)]
 pub struct Commit {
-	author: User,
-	body: Option<String>,
-	committer: User,
-	date: DateTime<Local>,
-	file_stats: Vec<FileStat>,
-	hash: String,
-	number_files_changed: usize,
-	insertions: usize,
-	deletions: usize,
+	pub(super) author: User,
+	pub(super) body: Option<String>,
+	pub(super) committer: User,
+	pub(super) date: DateTime<Local>,
+	pub(super) file_stats: Vec<FileStat>,
+	pub(super) hash: String,
+	pub(super) number_files_changed: usize,
+	pub(super) insertions: usize,
+	pub(super) deletions: usize,
 }
 
 fn load_commit_state(hash: &str, config: LoadCommitDiffOptions) -> Result<Commit, Error> {
diff --git a/src/show_commit/file_stat.rs b/src/show_commit/file_stat.rs
index 7831cf0..8d9456b 100644
--- a/src/show_commit/file_stat.rs
+++ b/src/show_commit/file_stat.rs
@@ -5,12 +5,12 @@ use crate::show_commit::status::Status;
 #[derive(Debug, Clone)]
 #[cfg_attr(test, derive(PartialEq))]
 pub struct FileStat {
-	status: Status,
-	to_name: String,
-	from_name: String,
-	largest_old_line_number: u32,
-	largest_new_line_number: u32,
-	deltas: Vec<Delta>,
+	pub(super) status: Status,
+	pub(super) to_name: String,
+	pub(super) from_name: String,
+	pub(super) largest_old_line_number: u32,
+	pub(super) largest_new_line_number: u32,
+	pub(super) deltas: Vec<Delta>,
 }
 
 impl FileStat {
diff --git a/src/show_commit/mod.rs b/src/show_commit/mod.rs
index 115c91d..c9206f3 100644
--- a/src/show_commit/mod.rs
+++ b/src/show_commit/mod.rs
@@ -10,6 +10,9 @@ mod user;
 mod util;
 mod view_builder;
 
+#[cfg(test)]
+mod tests;
+
 use crate::config::diff_ignore_whitespace_setting::DiffIgnoreWhitespaceSetting;
 use crate::config::diff_show_whitespace_setting::DiffShowWhitespaceSetting;
 use crate::config::Config;
@@ -88,7 +91,7 @@ impl<'s> ProcessModule for ShowCommit<'s> {
 					else {
 						let hash = commit.get_hash();
 						let max_index = hash.len().min(8);
-						format!("{:8} ", hash[0..max_index].to_string())
+						format!("{:8}", hash[0..max_index].to_string())
 					}
 					.as_str(),
 				),
diff --git a/src/show_commit/tests.rs b/src/show_commit/tests.rs
new file mode 100644
index 0000000..90bd5ab
--- /dev/null
+++ b/src/show_commit/tests.rs
@@ -0,0 +1,1293 @@
+use super::*;
+use crate::assert_process_result;
+use crate::assert_rendered_output;
+use crate::process::testutil::{process_module_test, TestContext, ViewState};
+use crate::show_commit::delta::Delta;
+use crate::show_commit::diff_line::DiffLine;
+use crate::show_commit::file_stat::FileStat;
+use crate::show_commit::origin::Origin;
+use crate::show_commit::status::Status;
+use crate::show_commit::user::User;
+use anyhow::anyhow;
+use chrono::Local;
+
+fn create_minimal_commit() -> Commit {
+	Commit {
+		author: User::new(None, None),
+		body: None,
+		committer: User::new(None, None),
+		date: Local::now(),
+		file_stats: vec![],
+		hash: String::from("0123456789abcdef0123456789abcdef"),
+		number_files_changed: 0,
+		insertions: 0,
+		deletions: 0,
+	}
+}
+
+#[test]
+#[serial_test::serial]
+fn load_commit_during_activate() {
+	process_module_test(
+		&["pick 18d82dcc4c36cade807d7cf79700b6bbad8080b9 comment1"],
+		ViewState::default(),
+		&[],
+		|test_context: TestContext<'_>| {
+			let mut module = ShowCommit::new(test_context.config);
+			assert_process_result!(test_context.activate(&mut module, State::List));
+			assert!(module.commit.is_some());
+		},
+	);
+}
+
+#[test]
+#[serial_test::serial]
+fn cached_commit_in_activate() {
+	process_module_test(
+		&["pick 18d82dcc4c36cade807d7cf79700b6bbad8080b9 comment1"],
+		ViewState::default(),
+		&[],
+		|test_context: TestContext<'_>| {
+			let mut module = ShowCommit::new(test_context.config);
+			assert_process_result!(test_context.activate(&mut module, State::List));
+			assert_process_result!(test_context.activate(&mut module, State::List));
+		},
+	);
+}
+
+#[test]
+#[serial_test::serial]
+fn activate_error() {
+	process_module_test(
+		&["pick aaaaaaaaaa comment1"],
+		ViewState::default(),
+		&[],
+		|test_context: TestContext<'_>| {
+			let mut module = ShowCommit::new(test_context.config);
+			assert_process_result!(
+				test_context.activate(&mut module, State::List),
+				state = State::List,
+				error = anyhow!(
+					"Error loading commit: aaaaaaaaaa: revspec 'aaaaaaaaaa' not found; class=Reference (4); \
+					 code=NotFound (-3)"
+				)
+			);
+		},
+	);
+}
+
+#[test]
+#[serial_test::serial]
+fn render_overview_minimal_commit() {
+	process_module_test(
+		&["pick 0123456789abcdef0123456789abcdef comment1"],
+		ViewState::default(),
+		&[],
+		|test_context: TestContext<'_>| {
+			let mut module = ShowCommit::new(test_context.config);
+			let commit = create_minimal_commit();
+			let commit_date = commit.get_date().format("%c %z").to_string();
+			module.commit = Some(commit);
+			assert_rendered_output!(
+				test_context.build_view_data(&mut module),
+				"{TITLE}{HELP}",
+				"{LEADING}",
+				"{IndicatorColor}Commit: {Normal}0123456789abcdef0123456789abcdef",
+				"{BODY}",
+				format!("{{IndicatorColor}}Date: {{Normal}}{}", commit_date).as_str(),
+				"",
+				"{IndicatorColor}0{Normal} files{Normal} with {DiffAddColor}0{Normal} insertions{Normal} and \
+				 {DiffRemoveColor}0{Normal} deletions"
+			);
+		},
+	);
+}
+
+#[test]
+#[serial_test::serial]
+fn render_overview_minimal_commit_compact() {
+	process_module_test(
+		&["pick 0123456789abcdef0123456789abcdef comment1"],
+		ViewState {
+			size: (33, 100),
+			..ViewState::default()
+		},
+		&[],
+		|test_context: TestContext<'_>| {
+			let mut module = ShowCommit::new(test_context.config);
+			let commit = create_minimal_commit();
+			let commit_date = commit.get_date().format("%c %z").to_string();
+			module.commit = Some(commit);
+			assert_rendered_output!(
+				test_context.build_view_data(&mut module),
+				"{TITLE}{HELP}",
+				"{LEADING}",
+				"{Normal}01234567",
+				"{BODY}",
+				format!("{{IndicatorColor}}D: {{Normal}}{}", commit_date).as_str(),
+				"",
+				"{IndicatorColor}0{Normal} / {DiffAddColor}0{Normal} / {DiffRemoveColor}0"
+			);
+		},
+	);
+}
+
+#[test]
+#[serial_test::serial]
+fn render_overview_with_author() {
+	process_module_test(
+		&["pick 0123456789abcdef0123456789abcdef comment1"],
+		ViewState::default(),
+		&[],
+		|test_context: TestContext<'_>| {
+			let mut module = ShowCommit::new(test_context.config);
+			let mut commit = create_minimal_commit();
+			let commit_date = commit.get_date().format("%c %z").to_string();
+			commit.author = User::new(Some("John Doe"), Some("john.doe@example.com"));
+			module.commit = Some(commit);
+			assert_rendered_output!(
+				test_context.build_view_data(&mut module),
+				"{TITLE}{HELP}",
+				"{LEADING}",
+				"{IndicatorColor}Commit: {Normal}0123456789abcdef0123456789abcdef",
+				"{BODY}",
+				format!("{{IndicatorColor}}Date: {{Normal}}{}", commit_date).as_str(),
+				"{IndicatorColor}Author: {Normal}John Doe <john.doe@example.com>",
+				"",
+				"{IndicatorColor}0{Normal} files{Normal} with {DiffAddColor}0{Normal} insertions{Normal} and \
+				 {DiffRemoveColor}0{Normal} deletions"
+			);
+		},
+	);
+}
+
+#[test]
+#[serial_test::serial]
+fn render_overview_with_author_compact() {
+	process_module_test(
+		&["pick 0123456789abcdef0123456789abcdef comment1"],
+		ViewState {
+			size: (33, 100),
+			..ViewState::default()
+		},
+		&[],
+		|test_context: TestContext<'_>| {
+			let mut module = ShowCommit::new(test_context.config);
+			let mut commit = create_minimal_commit();
+			let commit_date = commit.get_date().format("%c %z").to_string();
+			commit.author = User::new(Some("John Doe"), Some("john.doe@example.com"));
+			module.commit = Some(commit);
+			assert_rendered_output!(
+				test_context.build_view_data(&mut module),
+				"{TITLE}{HELP}",
+				"{LEADING}",
+				"{Normal}01234567",
+				"{BODY}",
+				format!("{{IndicatorColor}}D: {{Normal}}{}", commit_date).as_str(),
+				"{IndicatorColor}A: {Normal}John Doe <john.doe@example.com",
+				"",
+				"{IndicatorColor}0{Normal} / {DiffAddColor}0{Normal} / {DiffRemoveColor}0"
+			);
+		},
+	);
+}
+
+#[test]
+#[serial_test::serial]
+fn render_overview_with_committer() {
+	process_module_test(
+		&["pick 0123456789abcdef0123456789abcdef comment1"],
+		ViewState::default(),
+		&[],
+		|test_context: TestContext<'_>| {
+			let mut module = ShowCommit::new(test_context.config);
+			let mut commit = create_minimal_commit();
+			let commit_date = commit.get_date().format("%c %z").to_string();
+			commit.committer = User::new(Some("John Doe"), Some("john.doe@example.com"));
+			module.commit = Some(commit);
+			assert_rendered_output!(
+				test_context.build_view_data(&mut module),
+				"{TITLE}{HELP}",
+				"{LEADING}",
+				"{IndicatorColor}Commit: {Normal}0123456789abcdef0123456789abcdef",
+				"{BODY}",
+				format!("{{IndicatorColor}}Date: {{Normal}}{}", commit_date).as_str(),
+				"{IndicatorColor}Committer: {Normal}John Doe <john.doe@example.com>",
+				"",
+				"{IndicatorColor}0{Normal} files{Normal} with {DiffAddColor}0{Normal} insertions{Normal} and \
+				 {DiffRemoveColor}0{Normal} deletions"
+			);
+		},
+	);
+}
+
+#[test]
+#[serial_test::serial]
+fn render_overview_with_committer_compact() {
+	process_module_test(
+		&["pick 0123456789abcdef0123456789abcdef comment1"],
+		ViewState {
+			size: (33, 100),
+			..ViewState::default()
+		},
+		&[],
+		|test_context: TestContext<'_>| {
+			let mut module = ShowCommit::new(test_context.config);
+			let mut commit = create_minimal_commit();
+			let commit_date = commit.get_date().format("%c %z").to_string();
+			commit.committer = User::new(Some("John Doe"), Some("john.doe@example.com"));
+			module.commit = Some(commit);
+			assert_rendered_output!(
+				test_context.build_view_data(&mut module),
+				"{TITLE}{HELP}",
+				"{LEADING}",
+				"{Normal}01234567",
+				"{BODY}",
+				format!("{{IndicatorColor}}D: {{Normal}}{}", commit_date).as_str(),
+				"{IndicatorColor}C: {Normal}John Doe <john.doe@example.com",
+				"",
+				"{IndicatorColor}0{Normal} / {DiffAddColor}0{Normal} / {DiffRemoveColor}0"
+			);
+		},
+	);
+}
+
+#[test]
+#[serial_test::serial]
+fn render_overview_with_commit_body() {
+	process_module_test(
+		&["pick 0123456789abcdef0123456789abcdef comment1"],
+		ViewState::default(),
+		&[],
+		|test_context: TestContext<'_>| {
+			let mut module = ShowCommit::new(test_context.config);
+			let mut commit = create_minimal_commit();
+			let commit_date = commit.get_date().format("%c %z").to_string();
+			commit.body = Some(String::from("Commit title\n\nCommit body"));
+			module.commit = Some(commit);
+			assert_rendered_output!(
+				test_context.build_view_data(&mut module),
+				"{TITLE}{HELP}",
+				"{LEADING}",
+				"{IndicatorColor}Commit: {Normal}0123456789abcdef0123456789abcdef",
+				"{BODY}",
+				format!("{{IndicatorColor}}Date: {{Normal}}{}", commit_date).as_str(),
+				"{Normal}Commit title",
+				"",
+				"{Normal}Commit body",
+				"",
+				"{IndicatorColor}0{Normal} files{Normal} with {DiffAddColor}0{Normal} insertions{Normal} and \
+				 {DiffRemoveColor}0{Normal} deletions"
+			);
+		},
+	);
+}
+
+#[test]
+#[serial_test::serial]
+fn render_overview_with_file_stats() {
+	process_module_test(
+		&["pick 0123456789abcdef0123456789abcdef comment1"],
+		ViewState::default(),
+		&[],
+		|test_context: TestContext<'_>| {
+			let mut module = ShowCommit::new(test_context.config);
+			let mut commit = create_minimal_commit();
+			let commit_date = commit.get_date().format("%c %z").to_string();
+			commit.file_stats = vec![
+				FileStat::new("file.1a", "file.1b", Status::Renamed),
+				FileStat::new("file.2a", "file.2a", Status::Added),
+				FileStat::new("file.3a", "file.3a", Status::Deleted),
+				FileStat::new("file.4a", "file.4b", Status::Copied),
+				FileStat::new("file.5a", "file.5a", Status::Modified),
+				FileStat::new("file.6a", "file.6a", Status::Typechange),
+				FileStat::new("file.7a", "file.7b", Status::Other),
+			];
+			module.commit = Some(commit);
+			assert_rendered_output!(
+				test_context.build_view_data(&mut module),
+				"{TITLE}{HELP}",
+				"{LEADING}",
+				"{IndicatorColor}Commit: {Normal}0123456789abcdef0123456789abcdef",
+				"{BODY}",
+				format!("{{IndicatorColor}}Date: {{Normal}}{}", commit_date).as_str(),
+				"",
+				"{IndicatorColor}0{Normal} files{Normal} with {DiffAddColor}0{Normal} insertions{Normal} and \
+				 {DiffRemoveColor}0{Normal} deletions",
+				"{DiffChangeColor} renamed: {DiffRemoveColor}file.1b{Normal} → {DiffAddColor}file.1a",
+				"{DiffAddColor}   added: {DiffAddColor}file.2a",
+				"{DiffRemoveColor} deleted: {DiffRemoveColor}file.3a",
+				"{DiffAddColor}  copied: {Normal}file.4b{Normal} → {DiffAddColor}file.4a",
+				"{DiffChangeColor}modified: {DiffChangeColor}file.5a",
+				"{DiffChangeColor} changed: {DiffChangeColor}file.6a",
+				"{Normal} unknown: {Normal}file.7a"
+			);
+		},
+	);
+}
+
+#[test]
+#[serial_test::serial]
+fn render_overview_with_file_stats_compact() {
+	process_module_test(
+		&["pick 0123456789abcdef0123456789abcdef comment1"],
+		ViewState {
+			size: (33, 100),
+			..ViewState::default()
+		},
+		&[],
+		|test_context: TestContext<'_>| {
+			let mut module = ShowCommit::new(test_context.config);
+			let mut commit = create_minimal_commit();
+			let commit_date = commit.get_date().format("%c %z").to_string();
+			commit.file_stats = vec![
+				FileStat::new("file.1a", "file.1b", Status::Renamed),
+				FileStat::new("file.2a", "file.2a", Status::Added),
+				FileStat::new("file.3a", "file.3a", Status::Deleted),
+				FileStat::new("file.4a", "file.4b", Status::Copied),
+				FileStat::new("file.5a", "file.5a", Status::Modified),
+				FileStat::new("file.6a", "file.6a", Status::Typechange),
+				FileStat::new("file.7a", "file.7b", Status::Other),
+			];
+			module.commit = Some(commit);
+			assert_rendered_output!(
+				test_context.build_view_data(&mut module),
+				"{TITLE}{HELP}",
+				"{LEADING}",
+				"{Normal}01234567",
+				"{BODY}",
+				format!("{{IndicatorColor}}D: {{Normal}}{}", commit_date).as_str(),
+				"",
+				"{IndicatorColor}0{Normal} / {DiffAddColor}0{Normal} / {DiffRemoveColor}0",
+				"{DiffChangeColor}R {DiffRemoveColor}file.1b{Normal}→{DiffAddColor}file.1a",
+				"{DiffAddColor}A {DiffAddColor}file.2a",
+				"{DiffRemoveColor}D {DiffRemoveColor}file.3a",
+				"{DiffAddColor}C {Normal}file.4b{Normal}→{DiffAddColor}file.4a",
+				"{DiffChangeColor}M {DiffChangeColor}file.5a",
+				"{DiffChangeColor}T {DiffChangeColor}file.6a",
+				"{Normal}X {Normal}file.7a"
+			);
+		},
+	);
+}
+
+#[test]
+#[serial_test::serial]
+fn render_overview_single_file_changed() {
+	process_module_test(
+		&["pick 0123456789abcdef0123456789abcdef comment1"],
+		ViewState::default(),
+		&[],
+		|test_context: TestContext<'_>| {
+			let mut module = ShowCommit::new(test_context.config);
+			let mut commit = create_minimal_commit();
+			let commit_date = commit.get_date().format("%c %z").to_string();
+			commit.number_files_changed = 1;
+			module.commit = Some(commit);
+			assert_rendered_output!(
+				test_context.build_view_data(&mut module),
+				"{TITLE}{HELP}",
+				"{LEADING}",
+				"{IndicatorColor}Commit: {Normal}0123456789abcdef0123456789abcdef",
+				"{BODY}",
+				format!("{{IndicatorColor}}Date: {{Normal}}{}", commit_date).as_str(),
+				"",
+				"{IndicatorColor}1{Normal} file{Normal} with {DiffAddColor}0{Normal} insertions{Normal} and \
+				 {DiffRemoveColor}0{Normal} deletions"
+			);
+		},
+	);
+}
+
+#[test]
+#[serial_test::serial]
+fn render_overview_more_than_one_file_changed() {
+	process_module_test(
+		&["pick 0123456789abcdef0123456789abcdef comment1"],
+		ViewState::default(),
+		&[],
+		|test_context: TestContext<'_>| {
+			let mut module = ShowCommit::new(test_context.config);
+			let mut commit = create_minimal_commit();
+			let commit_date = commit.get_date().format("%c %z").to_string();
+			commit.number_files_changed = 2;
+			module.commit = Some(commit);
+			assert_rendered_output!(
+				test_context.build_view_data(&mut module),
+				"{TITLE}{HELP}",
+				"{LEADING}",
+				"{IndicatorColor}Commit: {Normal}0123456789abcdef0123456789abcdef",
+				"{BODY}",
+				format!("{{IndicatorColor}}Date: {{Normal}}{}", commit_date).as_str(),
+				"",
+				"{IndicatorColor}2{Normal} files{Normal} with {DiffAddColor}0{Normal} insertions{Normal} and \
+				 {DiffRemoveColor}0{Normal} deletions"
+			);
+		},
+	);
+}
+
+#[test]
+#[serial_test::serial]
+fn render_overview_single_insertion() {
+	process_module_test(
+		&["pick 0123456789abcdef0123456789abcdef comment1"],
+		ViewState::default(),
+		&[],
+		|test_context: TestContext<'_>| {
+			let mut module = ShowCommit::new(test_context.config);
+			let mut commit = create_minimal_commit();
+			let commit_date = commit.get_date().format("%c %z").to_string();
+			commit.insertions = 1;
+			module.commit = Some(commit);
+			assert_rendered_output!(
+				test_context.build_view_data(&mut module),
+				"{TITLE}{HELP}",
+				"{LEADING}",
+				"{IndicatorColor}Commit: {Normal}0123456789abcdef0123456789abcdef",
+				"{BODY}",
+				format!("{{IndicatorColor}}Date: {{Normal}}{}", commit_date).as_str(),
+				"",
+				"{IndicatorColor}0{Normal} files{Normal} with {DiffAddColor}1{Normal} insertion{Normal} and \
+				 {DiffRemoveColor}0{Normal} deletions"
+			);
+		},
+	);
+}
+
+#[test]
+#[serial_test::serial]
+fn render_overview_more_than_one_insertion() {
+	process_module_test(
+		&["pick 0123456789abcdef0123456789abcdef comment1"],
+		ViewState::default(),
+		&[],
+		|test_context: TestContext<'_>| {
+			let mut module = ShowCommit::new(test_context.config);
+			let mut commit = create_minimal_commit();
+			let commit_date = commit.get_date().format("%c %z").to_string();
+			commit.insertions = 2;
+			module.commit = Some(commit);
+			assert_rendered_output!(
+				test_context.build_view_data(&mut module),
+				"{TITLE}{HELP}",
+				"{LEADING}",
+				"{IndicatorColor}Commit: {Normal}0123456789abcdef0123456789abcdef",
+				"{BODY}",
+				format!("{{IndicatorColor}}Date: {{Normal}}{}", commit_date).as_str(),
+				"",
+				"{IndicatorColor}0{Normal} files{Normal} with {DiffAddColor}2{Normal} insertions{Normal} and \
+				 {DiffRemoveColor}0{Normal} deletions"
+			);
+		},
+	);
+}
+
+#[test]
+#[serial_test::serial]
+fn render_overview_single_deletion() {
+	process_module_test(
+		&["pick 0123456789abcdef0123456789abcdef comment1"],
+		ViewState::default(),
+		&[],
+		|test_context: TestContext<'_>| {
+			let mut module = ShowCommit::new(test_context.config);
+			let mut commit = create_minimal_commit();
+			let commit_date = commit.get_date().format("%c %z").to_string();
+			commit.deletions = 1;
+			module.commit = Some(commit);
+			assert_rendered_output!(
+				test_context.build_view_data(&mut module),
+				"{TITLE}{HELP}",
+				"{LEADING}",
+				"{IndicatorColor}Commit: {Normal}0123456789abcdef0123456789abcdef",
+				"{BODY}",
+				format!("{{IndicatorColor}}Date: {{Normal}}{}", commit_date).as_str(),
+				"",
+				"{IndicatorColor}0{Normal} files{Normal} with {DiffAddColor}0{Normal} insertions{Normal} and \
+				 {DiffRemoveColor}1{Normal} deletion"
+			);
+		},
+	);
+}
+
+#[test]
+#[serial_test::serial]
+fn render_overview_more_than_one_deletion() {
+	process_module_test(
+		&["pick 0123456789abcdef0123456789abcdef comment1"],
+		ViewState::default(),
+		&[],
+		|test_context: TestContext<'_>| {
+			let mut module = ShowCommit::new(test_context.config);
+			let mut commit = create_minimal_commit();
+			let commit_date = commit.get_date().format("%c %z").to_string();
+			commit.deletions = 2;
+			module.commit = Some(commit);
+			assert_rendered_output!(
+				test_context.build_view_data(&mut module),
+				"{TITLE}{HELP}",
+				"{LEADING}",
+				"{IndicatorColor}Commit: {Normal}0123456789abcdef0123456789abcdef",
+				"{BODY}",
+				format!("{{IndicatorColor}}Date: {{Normal}}{}", commit_date).as_str(),
+				"",
+				"{IndicatorColor}0{Normal} files{Normal} with {DiffAddColor}0{Normal} insertions{Normal} and \
+				 {DiffRemoveColor}2{Normal} deletions"
+			);
+		},
+	);
+}
+
+#[test]
+#[serial_test::serial]
+fn render_diff_minimal_commit() {
+	process_module_test(
+		&["pick 0123456789abcdef0123456789abcdef comment1"],
+		ViewState {
+			size: (50, 100),
+			..ViewState::default()
+		},
+		&[],
+		|test_context: TestContext<'_>| {
+			let mut config = test_context.config.clone();
+			config.diff_show_whitespace = DiffShowWhitespaceSetting::None;
+			let mut module = ShowCommit::new(&config);
+			module.commit = Some(create_minimal_commit());
+			module.state = ShowCommitState::Diff;
+			assert_rendered_output!(
+				test_context.build_view_data(&mut module),
+				"{TITLE}{HELP}",
+				"{LEADING}",
+				"{IndicatorColor}Commit: {Normal}0123456789abcdef0123456789abcdef",
+				"{IndicatorColor}0{Normal} files{Normal} with {DiffAddColor}0{Normal} insertions{Normal} and \
+				 {DiffRemoveColor}0{Normal} deletions",
+				"{BODY}",
+				"{Normal}{Pad ―,150}"
+			);
+		},
+	);
+}
+
+#[test]
+#[serial_test::serial]
+fn render_diff_minimal_commit_compact() {
+	process_module_test(
+		&["pick 0123456789abcdef0123456789abcdef comment1"],
+		ViewState {
+			size: (33, 100),
+			..ViewState::default()
+		},
+		&[],
+		|test_context: TestContext<'_>| {
+			let mut config = test_context.config.clone();
+			config.diff_show_whitespace = DiffShowWhitespaceSetting::None;
+			let mut module = ShowCommit::new(&config);
+			module.commit = Some(create_minimal_commit());
+			module.state = ShowCommitState::Diff;
+			assert_rendered_output!(
+				test_context.build_view_data(&mut module),
+				"{TITLE}{HELP}",
+				"{LEADING}",
+				"{Normal}01234567",
+				"{IndicatorColor}0{Normal} / {DiffAddColor}0{Normal} / {DiffRemoveColor}0",
+				"{BODY}",
+				"{Normal}{Pad ―,99}"
+			);
+		},
+	);
+}
+
+#[test]
+#[serial_test::serial]
+fn render_diff_basic_file_stats() {
+	process_module_test(
+		&["pick 0123456789abcdef0123456789abcdef comment1"],
+		ViewState {
+			size: (50, 100),
+			..ViewState::default()
+		},
+		&[],
+		|test_context: TestContext<'_>| {
+			let mut config = test_context.config.clone();
+			config.diff_show_whitespace = DiffShowWhitespaceSetting::None;
+			let mut module = ShowCommit::new(&config);
+			let mut commit = create_minimal_commit();
+			commit.file_stats = vec![
+				FileStat::new("file.1a", "file.1b", Status::Renamed),
+				FileStat::new("file.2a", "file.2a", Status::Added),
+				FileStat::new("file.3a", "file.3a", Status::Deleted),
+				FileStat::new("file.4a", "file.4b", Status::Copied),
+				FileStat::new("file.5a", "file.5a", Status::Modified),
+				FileStat::new("file.6a", "file.6a", Status::Typechange),
+				FileStat::new("file.7a", "file.7b", Status::Other),
+			];
+			module.commit = Some(commit);
+			module.state = ShowCommitState::Diff;
+			assert_rendered_output!(
+				test_context.build_view_data(&mut module),
+				"{TITLE}{HELP}",
+				"{LEADING}",
+				"{IndicatorColor}Commit: {Normal}0123456789abcdef0123456789abcdef",
+				"{IndicatorColor}0{Normal} files{Normal} with {DiffAddColor}0{Normal} insertions{Normal} and \
+				 {DiffRemoveColor}0{Normal} deletions",
+				"{BODY}",
+				"{Normal}{Pad ―,150}",
+				"{DiffChangeColor} renamed: {DiffRemoveColor}file.1b{Normal} → {DiffAddColor}file.1a",
+				"{Normal}{Pad ―,150}",
+				"{DiffAddColor}   added: {DiffAddColor}file.2a",
+				"{Normal}{Pad ―,150}",
+				"{DiffRemoveColor} deleted: {DiffRemoveColor}file.3a",
+				"{Normal}{Pad ―,150}",
+				"{DiffAddColor}  copied: {Normal}file.4b{Normal} → {DiffAddColor}file.4a",
+				"{Normal}{Pad ―,150}",
+				"{DiffChangeColor}modified: {DiffChangeColor}file.5a",
+				"{Normal}{Pad ―,150}",
+				"{DiffChangeColor} changed: {DiffChangeColor}file.6a",
+				"{Normal}{Pad ―,150}",
+				"{Normal} unknown: {Normal}file.7a"
+			);
+		},
+	);
+}
+
+#[test]
+#[serial_test::serial]
+fn render_diff_end_new_line_missing() {
+	process_module_test(
+		&["pick 0123456789abcdef0123456789abcdef comment1"],
+		ViewState {
+			size: (50, 100),
+			..ViewState::default()
+		},
+		&[],
+		|test_context: TestContext<'_>| {
+			let mut module = ShowCommit::new(test_context.config);
+			let mut commit = create_minimal_commit();
+			let mut file_stat = FileStat::new("file.txt", "file.txt", Status::Modified);
+			let mut delta = Delta::new("@@ -14,2 +13,3 @@ context", 14, 14, 0, 1);
+			delta.add_line(DiffLine::new(Origin::Addition, "new line", None, Some(14), false));
+			delta.add_line(DiffLine::new(Origin::Addition, "", None, Some(15), true));
+			file_stat.add_delta(delta);
+			commit.file_stats = vec![file_stat];
+			module.commit = Some(commit);
+			module.state = ShowCommitState::Diff;
+			assert_rendered_output!(
+				test_context.build_view_data(&mut module),
+				"{TITLE}{HELP}",
+				"{LEADING}",
+				"{IndicatorColor}Commit: {Normal}0123456789abcdef0123456789abcdef",
+				"{IndicatorColor}0{Normal} files{Normal} with {DiffAddColor}0{Normal} insertions{Normal} and \
+				 {DiffRemoveColor}0{Normal} deletions",
+				"{BODY}",
+				"{Normal}{Pad ―,150}",
+				"{DiffChangeColor}modified: {DiffChangeColor}file.txt",
+				"",
+				"{Normal,Dimmed}@@{DiffContextColor} -14,0 +14,1 {Normal,Dimmed}@@{DiffContextColor} context",
+				"{Normal,Dimmed}{Pad ┈,150}",
+				"{Normal}  {Normal} {Normal}14{Normal}| {DiffAddColor}new line",
+				"{Normal}       {DiffContextColor}\\ No newline at end of file"
+			);
+		},
+	);
+}
+
+#[test]
+#[serial_test::serial]
+fn render_diff_add_line() {
+	process_module_test(
+		&["pick 0123456789abcdef0123456789abcdef comment1"],
+		ViewState {
+			size: (50, 100),
+			..ViewState::default()
+		},
+		&[],
+		|test_context: TestContext<'_>| {
+			let mut config = test_context.config.clone();
+			config.diff_show_whitespace = DiffShowWhitespaceSetting::None;
+			let mut module = ShowCommit::new(&config);
+			let mut commit = create_minimal_commit();
+			let mut file_stat = FileStat::new("file.txt", "file.txt", Status::Modified);
+			let mut delta = Delta::new("@@ -14,2 +13,3 @@ context", 14, 14, 0, 1);
+			delta.add_line(DiffLine::new(Origin::Addition, "new line", None, Some(14), false));
+			file_stat.add_delta(delta);
+			commit.file_stats = vec![file_stat];
+			module.commit = Some(commit);
+			module.state = ShowCommitState::Diff;
+			assert_rendered_output!(
+				test_context.build_view_data(&mut module),
+				"{TITLE}{HELP}",
+				"{LEADING}",
+				"{IndicatorColor}Commit: {Normal}0123456789abcdef0123456789abcdef",
+				"{IndicatorColor}0{Normal} files{Normal} with {DiffAddColor}0{Normal} insertions{Normal} and \
+				 {DiffRemoveColor}0{Normal} deletions",
+				"{BODY}",
+				"{Normal}{Pad ―,150}",
+				"{DiffChangeColor}modified: {DiffChangeColor}file.txt",
+				"",
+				"{Normal,Dimmed}@@{DiffContextColor} -14,0 +14,1 {Normal,Dimmed}@@{DiffContextColor} context",
+				"{Normal,Dimmed}{Pad ┈,150}",
+				"{Normal}  {Normal} {Normal}14{Normal}| {DiffAddColor}new line"
+			);
+		},
+	);
+}
+
+#[test]
+#[serial_test::serial]
+fn render_diff_delete_line() {
+	process_module_test(
+		&["pick 0123456789abcdef0123456789abcdef comment1"],
+		ViewState {
+			size: (50, 100),
+			..ViewState::default()
+		},
+		&[],
+		|test_context: TestContext<'_>| {
+			let mut config = test_context.config.clone();
+			config.diff_show_whitespace = DiffShowWhitespaceSetting::None;
+			let mut module = ShowCommit::new(&config);
+			let mut commit = create_minimal_commit();
+			let mut file_stat = FileStat::new("file.txt", "file.txt", Status::Modified);
+			let mut delta = Delta::new("@@ -14,2 +13,3 @@ context", 14, 14, 0, 1);
+			delta.add_line(DiffLine::new(Origin::Deletion, "old line", Some(14), None, false));
+			file_stat.add_delta(delta);
+			commit.file_stats = vec![file_stat];
+			module.commit = Some(commit);
+			module.state = ShowCommitState::Diff;
+			assert_rendered_output!(
+				test_context.build_view_data(&mut module),
+				"{TITLE}{HELP}",
+				"{LEADING}",
+				"{IndicatorColor}Commit: {Normal}0123456789abcdef0123456789abcdef",
+				"{IndicatorColor}0{Normal} files{Normal} with {DiffAddColor}0{Normal} insertions{Normal} and \
+				 {DiffRemoveColor}0{Normal} deletions",
+				"{BODY}",
+				"{Normal}{Pad ―,150}",
+				"{DiffChangeColor}modified: {DiffChangeColor}file.txt",
+				"",
+				"{Normal,Dimmed}@@{DiffContextColor} -14,0 +14,1 {Normal,Dimmed}@@{DiffContextColor} context",
+				"{Normal,Dimmed}{Pad ┈,150}",
+				"{Normal}14{Normal} {Normal}  {Normal}| {DiffRemoveColor}old line"
+			);
+		},
+	);
+}
+
+#[test]
+#[serial_test::serial]
+fn render_diff_context_add_remove_lines() {
+	process_module_test(
+		&["pick 0123456789abcdef0123456789abcdef comment1"],
+		ViewState {
+			size: (50, 100),
+			..ViewState::default()
+		},
+		&[],
+		|test_context: TestContext<'_>| {
+			let mut config = test_context.config.clone();
+			config.diff_show_whitespace = DiffShowWhitespaceSetting::None;
+			let mut module = ShowCommit::new(&config);
+			let mut commit = create_minimal_commit();
+			let mut file_stat = FileStat::new("file.txt", "file.txt", Status::Modified);
+			let mut delta = Delta::new("@@ -14,2 +13,3 @@ context", 14, 14, 0, 1);
+			delta.add_line(DiffLine::new(Origin::Context, "context 1", Some(13), Some(13), false));
+			delta.add_line(DiffLine::new(Origin::Deletion, "old line", Some(14), None, false));
+			delta.add_line(DiffLine::new(Origin::Addition, "new line", None, Some(14), false));
+			delta.add_line(DiffLine::new(Origin::Context, "context 2", Some(15), Some(15), false));
+			file_stat.add_delta(delta);
+			commit.file_stats = vec![file_stat];
+			module.commit = Some(commit);
+			module.state = ShowCommitState::Diff;
+			assert_rendered_output!(
+				test_context.build_view_data(&mut module),
+				"{TITLE}{HELP}",
+				"{LEADING}",
+				"{IndicatorColor}Commit: {Normal}0123456789abcdef0123456789abcdef",
+				"{IndicatorColor}0{Normal} files{Normal} with {DiffAddColor}0{Normal} insertions{Normal} and \
+				 {DiffRemoveColor}0{Normal} deletions",
+				"{BODY}",
+				"{Normal}{Pad ―,150}",
+				"{DiffChangeColor}modified: {DiffChangeColor}file.txt",
+				"",
+				"{Normal,Dimmed}@@{DiffContextColor} -14,0 +14,1 {Normal,Dimmed}@@{DiffContextColor} context",
+				"{Normal,Dimmed}{Pad ┈,150}",
+				"{Normal}13{Normal} {Normal}13{Normal}| {DiffContextColor}context 1",
+				"{Normal}14{Normal} {Normal}  {Normal}| {DiffRemoveColor}old line",
+				"{Normal}  {Normal} {Normal}14{Normal}| {DiffAddColor}new line",
+				"{Normal}15{Normal} {Normal}15{Normal}| {DiffContextColor}context 2"
+			);
+		},
+	);
+}
+
+#[test]
+#[serial_test::serial]
+fn render_diff_add_line_with_show_whitespace() {
+	process_module_test(
+		&["pick 0123456789abcdef0123456789abcdef comment1"],
+		ViewState {
+			size: (50, 100),
+			..ViewState::default()
+		},
+		&[],
+		|test_context: TestContext<'_>| {
+			let mut config = test_context.config.clone();
+			config.diff_show_whitespace = DiffShowWhitespaceSetting::Both;
+			let mut module = ShowCommit::new(&config);
+			let mut commit = create_minimal_commit();
+			let mut file_stat = FileStat::new("file.txt", "file.txt", Status::Modified);
+			let mut delta = Delta::new("@@ -14,2 +13,3 @@ context", 14, 14, 0, 1);
+			delta.add_line(DiffLine::new(Origin::Addition, "new line", None, Some(14), false));
+			file_stat.add_delta(delta);
+			commit.file_stats = vec![file_stat];
+			module.commit = Some(commit);
+			module.state = ShowCommitState::Diff;
+			assert_rendered_output!(
+				test_context.build_view_data(&mut module),
+				"{TITLE}{HELP}",
+				"{LEADING}",
+				"{IndicatorColor}Commit: {Normal}0123456789abcdef0123456789abcdef",
+				"{IndicatorColor}0{Normal} files{Normal} with {DiffAddColor}0{Normal} insertions{Normal} and \
+				 {DiffRemoveColor}0{Normal} deletions",
+				"{BODY}",
+				"{Normal}{Pad ―,150}",
+				"{DiffChangeColor}modified: {DiffChangeColor}file.txt",
+				"",
+				"{Normal,Dimmed}@@{DiffContextColor} -14,0 +14,1 {Normal,Dimmed}@@{DiffContextColor} context",
+				"{Normal,Dimmed}{Pad ┈,150}",
+				"{Normal}  {Normal} {Normal}14{Normal}| {DiffAddColor}new line"
+			);
+		},
+	);
+}
+
+#[test]
+#[serial_test::serial]
+fn render_diff_delete_line_with_show_whitespace() {
+	process_module_test(
+		&["pick 0123456789abcdef0123456789abcdef comment1"],
+		ViewState {
+			size: (50, 100),
+			..ViewState::default()
+		},
+		&[],
+		|test_context: TestContext<'_>| {
+			let mut config = test_context.config.clone();
+			config.diff_show_whitespace = DiffShowWhitespaceSetting::Both;
+			let mut module = ShowCommit::new(&config);
+			let mut commit = create_minimal_commit();
+			let mut file_stat = FileStat::new("file.txt", "file.txt", Status::Modified);
+			let mut delta = Delta::new("@@ -14,2 +13,3 @@ context", 14, 14, 0, 1);
+			delta.add_line(DiffLine::new(Origin::Deletion, "old line", Some(14), None, false));
+			file_stat.add_delta(delta);
+			commit.file_stats = vec![file_stat];
+			module.commit = Some(commit);
+			module.state = ShowCommitState::Diff;
+			assert_rendered_output!(
+				test_context.build_view_data(&mut module),
+				"{TITLE}{HELP}",
+				"{LEADING}",
+				"{IndicatorColor}Commit: {Normal}0123456789abcdef0123456789abcdef",
+				"{IndicatorColor}0{Normal} files{Normal} with