Fix: use whole numbers for version, instead of numbers with fractional values.

Author: bjones1

client/src/CodeChatEditor.mts

@@ -70,6 +70,7 @@ import {
     UpdateMessageContents,
     CodeMirror,
     autosave_timeout_ms,
+    rand,
 } from "./shared_types.mjs";
 import { show_toast } from "./show_toast.mjs";
 
@@ -348,7 +349,7 @@ const save_lp = (is_dirty: boolean) => {
         update.contents = {
             metadata: current_metadata,
             source: code_mirror_diffable,
-            version: Math.random(),
+            version: rand(),
         };
     }
 

client/src/shared_types.mts

@@ -18,7 +18,10 @@
 // =============================================
 // The time, in ms, to wait between the last user edit and sending updated data to the Server.
 export const autosave_timeout_ms = 300;
-//
+
+// Produce a whole random number. Fractional numbers aren't consistently converted to the same number. Note that the mantissa of a JavaScript `Number` is 53 bits per the [docs](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number#number_encoding). To be certain, also round the result.
+export const rand = () => Math.round(Math.random() * 2 ** 53);
+
 // ### Message types
 //
 // These mirror the same definitions in the Rust webserver, so that the two can

extensions/VSCode/src/extension.ts

@@ -43,6 +43,7 @@ import {
     autosave_timeout_ms,
     EditorMessage,
     MessageResult,
+    rand,
     UpdateMessageContents,
 } from "../../../client/src/shared_types.mjs";
 import {
@@ -648,7 +649,7 @@ const send_update = (this_is_dirty: boolean) => {
                 const file_path = ate.document.fileName;
                 // Send contents only if necessary.
                 const option_contents: null | [string, number] = is_dirty
-                    ? [ate.document.getText(), (version = Math.random())]
+                    ? [ate.document.getText(), (version = rand())]
                     : null;
                 is_dirty = false;
                 console_log(

server/src/ide/filewatcher.rs

@@ -536,8 +536,8 @@ async fn processing_task(
                                                         doc: file_contents,
                                                         doc_blocks: vec![],
                                                     }),
-                                                    // The filewatcher doesn't store a version, since it only accepts plain (non-diff) results. Provide a version so the Client stays in sync with any diffs.
-                                                    version: random(),
+                                                    // The filewatcher doesn't store a version, since it only accepts plain (non-diff) results. Provide a version so the Client stays in sync with any diffs. Produce a whole number to avoid encoding difference with fractional values.
+                                                    version: random::<u64>() as f64,
                                                 }),
                                                 cursor_position: None,
                                                 scroll_position: None,

server/src/translation.rs

@@ -1046,7 +1046,8 @@ impl TranslationTask {
                                         self.code_mirror_doc_blocks.as_ref().unwrap(),
                                     )
                                 {
-                                    cfw_version = random();
+                                    // Use a whole number to avoid encoding differences with fractional values.
+                                    cfw_version = random::<u64>() as f64;
                                     // The Client needs an update.
                                     let client_contents = self.diff_code_mirror(
                                         cfw.metadata.clone(),