tests: supplement create_tree() with a builder-style API

The original form of `create_tree()` is limited to creating (valid
UTF-8) text files but cannot create binary files, executable
files, or symlinks. Dedicated helpers like `write_executable_file()` or
`write_symlink()` partially compensated for this, but required manually
assembling the tree in the test code.

This commit introduces `TestTreeBuilder` which provides an API to
successively add entries to a tree which can represent all of the above.
`TestTreeBuilder` can then create either a single `Tree`, or a resolved
`MergedTree`.

In addition to using `TestTreeBuilder` directly, `create_tree_with()`
and `create_single_tree_with()` accept a closure which receives a
`TestTreeBuilder`. This allows test code to quickly describe the tree
without requiring the a named builder at caller scope. Riffing off
the familiar function names should help in discovering the new builder
facilities. However, it is completely possible to use `TestTreeBuilder`
directly, if preferred.

Author: jgreitemann

cli/src/merge_tools/builtin.rs

@@ -863,17 +863,11 @@ mod tests {
 
         let added_executable_file_path = repo_path("executable_file");
         let left_tree = testutils::create_tree(&test_repo.repo, &[]);
-        let right_tree = {
-            // let store = test_repo.repo.store();
-            let mut tree_builder = store.tree_builder(store.empty_tree_id().clone());
-            testutils::write_executable_file(
-                &mut tree_builder,
-                added_executable_file_path,
-                "executable",
-            );
-            let id = tree_builder.write_tree().unwrap();
-            MergedTree::resolved(store.get_tree(RepoPathBuf::root(), &id).unwrap())
-        };
+        let right_tree = testutils::create_tree_with(&test_repo.repo, |builder| {
+            builder
+                .file(added_executable_file_path, "executable")
+                .executable(true);
+        });
 
         let (changed_files, files) = make_diff(store, &left_tree, &right_tree);
         insta::assert_debug_snapshot!(changed_files, @r#"

lib/tests/test_fix.rs

@@ -14,9 +14,7 @@
 
 use std::collections::HashMap;
 use std::collections::HashSet;
-use std::sync::Arc;
 
-use itertools::Itertools as _;
 use jj_lib::backend::CommitId;
 use jj_lib::backend::FileId;
 use jj_lib::backend::MergedTreeId;
@@ -26,13 +24,12 @@ use jj_lib::fix::FileToFix;
 use jj_lib::fix::FixError;
 use jj_lib::fix::ParallelFileFixer;
 use jj_lib::matchers::EverythingMatcher;
-use jj_lib::merged_tree::MergedTree;
-use jj_lib::repo::ReadonlyRepo;
 use jj_lib::repo::Repo as _;
 use jj_lib::store::Store;
 use jj_lib::transaction::Transaction;
 use pollster::FutureExt as _;
 use testutils::create_tree;
+use testutils::create_tree_with;
 use testutils::read_file;
 use testutils::repo_path;
 use testutils::TestRepo;
@@ -93,17 +90,6 @@ fn fix_file(store: &Store, file_to_fix: &FileToFix) -> Result<Option<FileId>, Fi
     }
 }
 
-fn create_tree_helper(
-    repo: &Arc<ReadonlyRepo>,
-    path_and_content: &[(String, String)],
-) -> MergedTree {
-    let content_map = path_and_content
-        .iter()
-        .map(|p| (repo_path(&p.0), p.1.as_str()))
-        .collect_vec();
-    create_tree(repo, &content_map)
-}
-
 fn create_commit(tx: &mut Transaction, parents: Vec<CommitId>, tree_id: MergedTreeId) -> CommitId {
     tx.repo_mut()
         .new_commit(parents, tree_id)
@@ -418,13 +404,11 @@ fn test_parallel_fixer_fixes_files() {
     let repo = &test_repo.repo;
 
     let mut tx = repo.start_transaction();
-    let mut path_contents1 = vec![];
-    for i in 0..100 {
-        let path = format!("file{i}");
-        let content = format!("fixme:content{i}");
-        path_contents1.push((path, content));
-    }
-    let tree1 = create_tree_helper(repo, &path_contents1);
+    let tree1 = create_tree_with(repo, |builder| {
+        for i in 0..100 {
+            builder.file(repo_path(&format!("file{i}")), format!("fixme:content{i}"));
+        }
+    });
     let commit_a = create_commit(
         &mut tx,
         vec![repo.store().root_commit_id().clone()],
@@ -444,13 +428,11 @@ fn test_parallel_fixer_fixes_files() {
     )
     .unwrap();
 
-    let mut expected_path_contents = vec![];
-    for i in 0..100 {
-        let path = format!("file{i}");
-        let content = format!("CONTENT{i}");
-        expected_path_contents.push((path, content));
-    }
-    let expected_tree_a = create_tree_helper(repo, &expected_path_contents);
+    let expected_tree_a = create_tree_with(repo, |builder| {
+        for i in 0..100 {
+            builder.file(repo_path(&format!("file{i}")), format!("CONTENT{i}"));
+        }
+    });
 
     assert_eq!(summary.rewrites.len(), 1);
     assert!(summary.rewrites.contains_key(&commit_a));
@@ -470,13 +452,11 @@ fn test_parallel_fixer_does_not_change_content() {
     let repo = &test_repo.repo;
 
     let mut tx = repo.start_transaction();
-    let mut path_contents1 = vec![];
-    for i in 0..100 {
-        let path = format!("file{i}");
-        let content = format!("content{i}");
-        path_contents1.push((path, content));
-    }
-    let tree1 = create_tree_helper(repo, &path_contents1);
+    let tree1 = create_tree_with(repo, |builder| {
+        for i in 0..100 {
+            builder.file(repo_path(&format!("file{i}")), format!("content{i}"));
+        }
+    });
     let commit_a = create_commit(
         &mut tx,
         vec![repo.store().root_commit_id().clone()],
@@ -507,19 +487,19 @@ fn test_parallel_fixer_no_changes_upon_partial_failure() {
     let repo = &test_repo.repo;
 
     let mut tx = repo.start_transaction();
-    let mut path_contents1 = vec![];
-    for i in 0..100 {
-        let path = format!("file{i}");
-        let content = if i == 7 {
-            format!("error:boo{i}")
-        } else if i % 3 == 0 {
-            format!("fixme:content{i}")
-        } else {
-            format!("foobar:{i}")
-        };
-        path_contents1.push((path, content));
-    }
-    let tree1 = create_tree_helper(repo, &path_contents1);
+    let tree1 = create_tree_with(repo, |builder| {
+        for i in 0..100 {
+            let contents = if i == 7 {
+                format!("error:boo{i}")
+            } else if i % 3 == 0 {
+                format!("fixme:content{i}")
+            } else {
+                format!("foobar:{i}")
+            };
+
+            builder.file(repo_path(&format!("file{i}")), &contents);
+        }
+    });
     let commit_a = create_commit(
         &mut tx,
         vec![repo.store().root_commit_id().clone()],

lib/tests/test_git.rs

@@ -29,11 +29,9 @@ use itertools::Itertools as _;
 use jj_lib::backend::BackendError;
 use jj_lib::backend::ChangeId;
 use jj_lib::backend::CommitId;
-use jj_lib::backend::MergedTreeId;
 use jj_lib::backend::MillisSinceEpoch;
 use jj_lib::backend::Signature;
 use jj_lib::backend::Timestamp;
-use jj_lib::backend::TreeValue;
 use jj_lib::commit::Commit;
 use jj_lib::commit_builder::CommitBuilder;
 use jj_lib::config::ConfigLayer;
@@ -68,7 +66,6 @@ use jj_lib::settings::GitSettings;
 use jj_lib::settings::UserSettings;
 use jj_lib::signing::Signer;
 use jj_lib::str_util::StringPattern;
-use jj_lib::tree_builder::TreeBuilder;
 use jj_lib::workspace::Workspace;
 use maplit::btreemap;
 use maplit::hashset;
@@ -78,7 +75,6 @@ use testutils::base_user_config;
 use testutils::commit_transactions;
 use testutils::create_random_commit;
 use testutils::repo_path;
-use testutils::repo_path_buf;
 use testutils::write_random_commit;
 use testutils::CommitGraphBuilder;
 use testutils::TestRepo;
@@ -2559,30 +2555,20 @@ fn test_reset_head_with_index_no_conflict() {
     let mut_repo = tx.repo_mut();
 
     // Build tree containing every mode of file
-    let tree_id = {
-        let mut tree_builder =
-            TreeBuilder::new(repo.store().clone(), repo.store().empty_tree_id().clone());
-        testutils::write_normal_file(
-            &mut tree_builder,
-            repo_path("some/dir/normal-file"),
-            "file\n",
+    let tree_id = testutils::create_tree_with(&repo, |builder| {
+        builder
+            .file(repo_path("some/dir/normal-file"), "file\n")
+            .executable(false);
+        builder
+            .file(repo_path("some/dir/executable-file"), "file\n")
+            .executable(true);
+        builder.symlink(repo_path("some/dir/symlink"), "./normal-file");
+        builder.submodule(
+            repo_path("some/dir/commit"),
+            testutils::write_random_commit(mut_repo).id().clone(),
         );
-        testutils::write_executable_file(
-            &mut tree_builder,
-            repo_path("some/dir/executable-file"),
-            "file\n",
-        );
-        testutils::write_symlink(
-            &mut tree_builder,
-            repo_path("some/dir/symlink"),
-            "./normal-file",
-        );
-        tree_builder.set(
-            repo_path_buf("some/dir/commit"),
-            TreeValue::GitSubmodule(testutils::write_random_commit(mut_repo).id().clone()),
-        );
-        MergedTreeId::resolved(tree_builder.write_tree().unwrap())
-    };
+    })
+    .id();
 
     let parent_commit = mut_repo
         .new_commit(vec![repo.store().root_commit_id().clone()], tree_id.clone())
@@ -2622,76 +2608,50 @@ fn test_reset_head_with_index_merge_conflict() {
     let mut_repo = tx.repo_mut();
 
     // Build conflict trees containing every mode of file
-    let base_tree_id = {
-        let mut tree_builder =
-            TreeBuilder::new(repo.store().clone(), repo.store().empty_tree_id().clone());
-        testutils::write_normal_file(
-            &mut tree_builder,
-            repo_path("some/dir/normal-file"),
-            "base\n",
-        );
-        testutils::write_executable_file(
-            &mut tree_builder,
-            repo_path("some/dir/executable-file"),
-            "base\n",
-        );
-        testutils::write_symlink(
-            &mut tree_builder,
-            repo_path("some/dir/symlink"),
-            "./normal-file",
-        );
-        tree_builder.set(
-            repo_path_buf("some/dir/commit"),
-            TreeValue::GitSubmodule(testutils::write_random_commit(mut_repo).id().clone()),
-        );
-        MergedTreeId::resolved(tree_builder.write_tree().unwrap())
-    };
-
-    let left_tree_id = {
-        let mut tree_builder =
-            TreeBuilder::new(repo.store().clone(), repo.store().empty_tree_id().clone());
-        testutils::write_normal_file(
-            &mut tree_builder,
-            repo_path("some/dir/normal-file"),
-            "left\n",
-        );
-        testutils::write_executable_file(
-            &mut tree_builder,
-            repo_path("some/dir/executable-file"),
-            "left\n",
-        );
-        testutils::write_symlink(
-            &mut tree_builder,
-            repo_path("some/dir/symlink"),
-            "./executable-file",
+    let base_tree_id = testutils::create_tree_with(&repo, |builder| {
+        builder
+            .file(repo_path("some/dir/normal-file"), "base\n")
+            .executable(false);
+        builder
+            .file(repo_path("some/dir/executable-file"), "base\n")
+            .executable(true);
+        builder.symlink(repo_path("some/dir/symlink"), "./normal-file");
+        builder.submodule(
+            repo_path("some/dir/commit"),
+            testutils::write_random_commit(mut_repo).id().clone(),
         );
-        tree_builder.set(
-            repo_path_buf("some/dir/commit"),
-            TreeValue::GitSubmodule(testutils::write_random_commit(mut_repo).id().clone()),
-        );
-        MergedTreeId::resolved(tree_builder.write_tree().unwrap())
-    };
-
-    let right_tree_id = {
-        let mut tree_builder =
-            TreeBuilder::new(repo.store().clone(), repo.store().empty_tree_id().clone());
-        testutils::write_normal_file(
-            &mut tree_builder,
-            repo_path("some/dir/normal-file"),
-            "right\n",
-        );
-        testutils::write_executable_file(
-            &mut tree_builder,
-            repo_path("some/dir/executable-file"),
-            "right\n",
+    })
+    .id();
+
+    let left_tree_id = testutils::create_tree_with(&repo, |builder| {
+        builder
+            .file(repo_path("some/dir/normal-file"), "left\n")
+            .executable(false);
+        builder
+            .file(repo_path("some/dir/executable-file"), "left\n")
+            .executable(true);
+        builder.symlink(repo_path("some/dir/symlink"), "./executable-file");
+        builder.submodule(
+            repo_path("some/dir/commit"),
+            testutils::write_random_commit(mut_repo).id().clone(),
         );
-        testutils::write_symlink(&mut tree_builder, repo_path("some/dir/symlink"), "./commit");
-        tree_builder.set(
-            repo_path_buf("some/dir/commit"),
-            TreeValue::GitSubmodule(testutils::write_random_commit(mut_repo).id().clone()),
+    })
+    .id();
+
+    let right_tree_id = testutils::create_tree_with(&repo, |builder| {
+        builder
+            .file(repo_path("some/dir/normal-file"), "right\n")
+            .executable(false);
+        builder
+            .file(repo_path("some/dir/executable-file"), "right\n")
+            .executable(true);
+        builder.symlink(repo_path("some/dir/symlink"), "./commit");
+        builder.submodule(
+            repo_path("some/dir/commit"),
+            testutils::write_random_commit(mut_repo).id().clone(),
         );
-        MergedTreeId::resolved(tree_builder.write_tree().unwrap())
-    };
+    })
+    .id();
 
     let base_commit = mut_repo
         .new_commit(
@@ -2756,19 +2716,14 @@ fn test_reset_head_with_index_file_directory_conflict() {
     let mut_repo = tx.repo_mut();
 
     // Build conflict trees containing file-directory conflict
-    let left_tree_id = {
-        let mut tree_builder =
-            TreeBuilder::new(repo.store().clone(), repo.store().empty_tree_id().clone());
-        testutils::write_normal_file(&mut tree_builder, repo_path("test/dir/file"), "dir\n");
-        MergedTreeId::resolved(tree_builder.write_tree().unwrap())
-    };
-
-    let right_tree_id = {
-        let mut tree_builder =
-            TreeBuilder::new(repo.store().clone(), repo.store().empty_tree_id().clone());
-        testutils::write_normal_file(&mut tree_builder, repo_path("test"), "file\n");
-        MergedTreeId::resolved(tree_builder.write_tree().unwrap())
-    };
+    let left_tree_id = testutils::create_tree_with(&repo, |builder| {
+        builder.file(repo_path("test/dir/file"), "dir\n");
+    })
+    .id();
+    let right_tree_id = testutils::create_tree_with(&repo, |builder| {
+        builder.file(repo_path("test"), "file\n");
+    })
+    .id();
 
     let left_commit = mut_repo
         .new_commit(