more comments to clarify things in the code

.travis.yml

@@ -14,7 +14,10 @@ jobs:
     - stage: test
       rust: stable
       script: |
+        # the unit tests for all crates (without mocking the network)
+        # run single-threaded because some tests change environment variables, which is not thread-safe
         cargo test --package notion-core --package notion-fail --package node-archive --package notion-fail-derive --package progress-read -- --test-threads=1 &&
+        # the acceptance tests, using network mocks
         cargo test --features mock-network
     - stage: publish
       # Conditional builds: https://docs.travis-ci.com/user/conditional-builds-stages-jobs/

appveyor.yml

@@ -118,5 +118,8 @@ build: false
 #directly or perform other testing commands. Rust will automatically be placed in the PATH
 # environment variable.
 test_script:
+  # the unit tests for all crates (without mocking the network)
+  # run single-threaded because some tests change environment variables, which is not thread-safe
   - cargo test --package notion-core --package notion-fail --package node-archive --package notion-fail-derive --package progress-read -- --test-threads=1 &&
+    # the acceptance tests, using network mocks
     cargo test --features mock-network

crates/notion-core/src/path/windows.rs

@@ -170,6 +170,7 @@ pub fn shim_file(toolname: &str) -> Fallible<PathBuf> {
 //                         catalog.toml                user_catalog_file
 
 fn local_data_root() -> Fallible<PathBuf> {
+    // used to sandbox the acceptance test environment
     if let Some(home_dir) = env::home_dir() {
         return Ok(home_dir.join("AppData").join("Local").join("Notion"));
     } else {