Use proper directory for cache files (#1763)

Operating systems have defined directories for cache files.
That allows them to do smart things such as leaving them out when doing a backup,
or deleting them when disk space gets low.

Also a %home%\.deno folder on windows made no sense whatsoever.

Fixes #481

1 files changed, 7 insertions, 1 deletions

diff --git a/src/deno_dir.rs b/src/deno_dir.rs
index 9d175077a..bcde87927 100644
--- a/src/deno_dir.rs
+++ b/src/deno_dir.rs
@@ -63,7 +63,13 @@ impl DenoDir {
   ) -> std::io::Result<Self> {
     // Only setup once.
     let home_dir = dirs::home_dir().expect("Could not get home directory.");
-    let default = home_dir.join(".deno");
+    let fallback = home_dir.join(".deno");
+    // We use the OS cache dir because all files deno writes are cache files
+    // Once that changes we need to start using different roots if DENO_DIR
+    // is not set, and keep a single one if it is.
+    let default = dirs::cache_dir()
+      .map(|d| d.join("deno"))
+      .unwrap_or(fallback);
 
     let root: PathBuf = custom_root.unwrap_or(default);
     let gen = root.as_path().join("gen");