review

Author: fhammerschmidt

packages/dev-playground/src/Main.res

@@ -658,6 +658,8 @@ module App = {
     let urlTimerId: ref<option<int>> = ref(None)
     let toastTimerId: ref<option<int>> = ref(None)
     let firstCompilerLoad = ref(true)
+    let compilerLoadSequence = ref(0)
+    let compileSequence = ref(0)
     let shareToast: Signal.t<option<string>> = Signal.make(None)
 
     let syncEditorState = event => {
@@ -685,6 +687,9 @@ module App = {
     }
 
     let compileNow = () => {
+      compileSequence := compileSequence.contents + 1
+      let sequence = compileSequence.contents
+
       let run = async () => {
         switch Signal.peek(status) {
         | Loading => ()
@@ -693,11 +698,19 @@ module App = {
           Signal.set(status, Compiling)
           try {
             let result = await CompilerApi.compile(Signal.peek(source), currentConfig())
-            Signal.set(compileResult, Some(result))
-            Signal.set(status, Ready)
+            if sequence === compileSequence.contents {
+              Signal.set(compileResult, Some(result))
+              Signal.set(status, Ready)
+            }
           } catch {
-          | JsExn(obj) => Signal.set(status, Failed(Browser.jsErrorMessage(obj)))
-          | _ => Signal.set(status, Failed("Compilation failed"))
+          | JsExn(obj) =>
+            if sequence === compileSequence.contents {
+              Signal.set(status, Failed(Browser.jsErrorMessage(obj)))
+            }
+          | _ =>
+            if sequence === compileSequence.contents {
+              Signal.set(status, Failed("Compilation failed"))
+            }
           }
         }
       }
@@ -768,35 +781,47 @@ module App = {
     }
 
     let loadCompiler = (version, compileAfterLoad) => {
+      compilerLoadSequence := compilerLoadSequence.contents + 1
+      compileSequence := compileSequence.contents + 1
+      let sequence = compilerLoadSequence.contents
+
       let load = async () => {
         try {
           Signal.set(status, Loading)
           Signal.set(compileResult, None)
           let info = await CompilerApi.init(version)
-          let useInitialSettings = firstCompilerLoad.contents
-          firstCompilerLoad := false
-          Signal.set(compilerInfo, Some(info))
-          Signal.set(compilerVersion, info.bundleId)
-          Signal.set(moduleSystem, useInitialSettings ? initialModuleSystem : info.moduleSystem)
-          Signal.set(warnFlags, useInitialSettings ? initialWarnFlags : info.warnFlags)
-          Signal.set(
-            jsxPreserveMode,
-            useInitialSettings ? initialJsxPreserveMode : info.jsxPreserveMode,
-          )
-          Signal.set(
-            experimentalFeatures,
-            useInitialSettings ? initialExperimentalFeatures : info.experimentalFeatures,
-          )
-          Signal.set(status, Ready)
-          if !useInitialSettings {
-            scheduleUrlSync()
-          }
-          if compileAfterLoad {
-            compileNow()
+          if sequence === compilerLoadSequence.contents {
+            let useInitialSettings = firstCompilerLoad.contents
+            firstCompilerLoad := false
+            Signal.set(compilerInfo, Some(info))
+            Signal.set(compilerVersion, info.bundleId)
+            Signal.set(moduleSystem, useInitialSettings ? initialModuleSystem : info.moduleSystem)
+            Signal.set(warnFlags, useInitialSettings ? initialWarnFlags : info.warnFlags)
+            Signal.set(
+              jsxPreserveMode,
+              useInitialSettings ? initialJsxPreserveMode : info.jsxPreserveMode,
+            )
+            Signal.set(
+              experimentalFeatures,
+              useInitialSettings ? initialExperimentalFeatures : info.experimentalFeatures,
+            )
+            Signal.set(status, Ready)
+            if !useInitialSettings {
+              scheduleUrlSync()
+            }
+            if compileAfterLoad {
+              compileNow()
+            }
           }
         } catch {
-        | JsExn(obj) => Signal.set(status, Failed(Browser.jsErrorMessage(obj)))
-        | _ => Signal.set(status, Failed("Compiler failed to load"))
+        | JsExn(obj) =>
+          if sequence === compilerLoadSequence.contents {
+            Signal.set(status, Failed(Browser.jsErrorMessage(obj)))
+          }
+        | _ =>
+          if sequence === compilerLoadSequence.contents {
+            Signal.set(status, Failed("Compiler failed to load"))
+          }
         }
       }
 

packages/dev-playground/src/UrlState.js

@@ -4,11 +4,8 @@ const maxEncodedCodeLength = 300 * 1024;
 const maxDecodedSourceLength = 200 * 1024;
 let replaceSequence = 0;
 
-function supportsCompression() {
-  return (
-    typeof CompressionStream !== "undefined" &&
-    typeof DecompressionStream !== "undefined"
-  );
+function supportsDecompression() {
+  return typeof DecompressionStream !== "undefined";
 }
 
 function normalizeModuleSystem(value, fallback) {
@@ -45,13 +42,6 @@ function base64UrlToBytes(value) {
   return bytes;
 }
 
-async function gzip(bytes) {
-  const stream = new Blob([bytes])
-    .stream()
-    .pipeThrough(new CompressionStream("gzip"));
-  return new Uint8Array(await new Response(stream).arrayBuffer());
-}
-
 async function gunzip(bytes) {
   const stream = new Blob([bytes])
     .stream()
@@ -61,23 +51,19 @@ async function gunzip(bytes) {
 
 async function encodeCode(source) {
   const sourceBytes = textEncoder.encode(source);
-
-  if (supportsCompression()) {
-    try {
-      const compressedBytes = await gzip(sourceBytes);
-      if (compressedBytes.length < sourceBytes.length) {
-        return `z:${bytesToBase64Url(compressedBytes)}`;
-      }
-    } catch {
-      // Fall through to plain base64-url encoding.
-    }
-  }
-
+  // Keep newly generated share links browser-portable. Older z: links are still
+  // decoded when the browser exposes DecompressionStream.
   return `b:${bytesToBase64Url(sourceBytes)}`;
 }
 
 async function decodeCode(encoded) {
   if (encoded.startsWith("z:")) {
+    if (!supportsDecompression()) {
+      throw new Error(
+        "Compressed shared links require browser DecompressionStream support",
+      );
+    }
+
     const compressedBytes = base64UrlToBytes(encoded.slice(2));
     return textDecoder.decode(await gunzip(compressedBytes));
   }
@@ -161,7 +147,8 @@ export async function initialSource(defaultSource) {
   try {
     const decoded = await decodeCode(encoded);
     return decoded.length <= maxDecodedSourceLength ? decoded : defaultSource;
-  } catch {
+  } catch (error) {
+    console.warn("Could not restore shared playground source", error);
     return defaultSource;
   }
 }