fix: #7614 - rebuild every time on macos because of Info.plist changes

[olexiyb]

According to macos documentation

This key is a machine-readable string composed of one to three period-separated integers, such as 10.14.1. The string can only contain numeric characters (0-9) and periods.

Each integer provides information about the build version in the format [Major].[Minor].[Patch]:

Major: A major revision number.

Minor: A minor revision number.

Patch: A maintenance release number.

You can include more integers but the system ignores them.

Current logic of the build prepare Info.plist with added timestamp at the end, this cause rebuild each restart even if not needed. Because You can include more integers but the system ignores them it does not make any sense to add timestamp

I also have to check Info.plist content from previous build with new build. If no changes just skip the write

This should solve #7614

[lucasfernog]

nice catch, can you clean this up so it only serializes the plist once?

diff --git a/core/tauri-codegen/src/context.rs b/core/tauri-codegen/src/context.rs
index 59e9a78ef..ace1e345a 100644
--- a/core/tauri-codegen/src/context.rs
+++ b/core/tauri-codegen/src/context.rs
@@ -4,6 +4,7 @@
 
 use std::collections::BTreeMap;
 use std::convert::identity;
+use std::io::BufWriter;
 use std::path::{Path, PathBuf};
 use std::{ffi::OsStr, str::FromStr};
 
@@ -328,18 +329,20 @@ pub fn context_codegen(data: ContextData) -> Result<TokenStream, EmbeddedAssetsE
         plist.insert("CFBundleVersion".into(), version.clone().into());
       }
     }
-    
+
     let plist_file = out_dir.join("Info.plist");
-    let old = if plist_file.exists() {
-      plist::Value::from_file(&plist_file).expect("failed to read old Info.plist")
-    } else {
-      plist::Value::Dictionary(Default::default())
-    };
-    let old = serde_json::to_string(&old).unwrap();
-    let n = serde_json::to_string(&info_plist).unwrap();
-    if old.ne(&n) {
-      info_plist.to_file_xml(plist_file).expect("failed to write Info.plist");
+
+    let mut plist_contents = BufWriter::new(Vec::new());
+    info_plist
+      .to_writer_xml(&mut plist_contents)
+      .expect("failed to serialize plist");
+    let plist_contents =
+      String::from_utf8_lossy(&plist_contents.into_inner().unwrap()).into_owned();
+
+    if plist_contents != std::fs::read_to_string(&plist_file).unwrap_or_default() {
+      std::fs::write(&plist_file, &plist_contents).expect("failed to write Info.plist");
     }
+
     quote!({
       tauri::embed_plist::embed_info_plist!(concat!(std::env!("OUT_DIR"), "/Info.plist"));
     })

[lucasfernog]

must fix clippy and also add a change file in the .changes folder:

.changes/fix-build-script-rerun-macos.md

---
"tauri-codegen": patch:bug
---

Fixes Info.plist rewriting always triggering build to rerun.