From cdb4dd6d9c362ec46dc967845cdc61d3f0cddac1 Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Thu, 10 Oct 2019 16:55:30 +0200
Subject: [PATCH 01/11] Use transform classes

---
 cli/asc.js                           | 30 +++++++++++++++++++---------
 cli/transform.d.ts                   | 19 +++++++++++++++---
 cli/transform.js                     |  5 +++++
 examples/transform/assembly/index.ts |  1 +
 examples/transform/mytransform.js    | 12 +++++++++++
 examples/transform/package.json      |  5 +++++
 6 files changed, 60 insertions(+), 12 deletions(-)
 create mode 100644 cli/transform.js
 create mode 100644 examples/transform/assembly/index.ts
 create mode 100644 examples/transform/mytransform.js
 create mode 100644 examples/transform/package.json

diff --git a/cli/asc.js b/cli/asc.js
index 4ee989d100..3af3137e92 100644
--- a/cli/asc.js
+++ b/cli/asc.js
@@ -212,15 +212,27 @@ exports.main = function main(argv, options, callback) {
   // Set up transforms
   const transforms = [];
   if (args.transform) {
-    args.transform.forEach(transform =>
-      transforms.push(
-        require(
-          path.isAbsolute(transform = transform.trim())
-            ? transform
-            : path.join(process.cwd(), transform)
-        )
-      )
-    );
+    class Transform {
+      baseDir = baseDir;
+      writeFile = writeFile;
+      readFile = readFile;
+      listFiles = listFiles;
+    }
+    args.transform.forEach(filename => {
+      const ctor = require(
+        path.isAbsolute(filename = filename.trim())
+          ? filename
+          : path.join(process.cwd(), filename)
+      );
+      let impl;
+      if (typeof ctor === "function") {
+        Object.setPrototypeOf(ctor, Transform);
+        impl = new ctor();
+      } else {
+        impl = ctor; // legacy module
+      }
+      transforms.push(impl);
+    });
   }
   function applyTransform(name, ...args) {
     transforms.forEach(transform => {
diff --git a/cli/transform.d.ts b/cli/transform.d.ts
index 9bc060b6df..82085bf878 100644
--- a/cli/transform.d.ts
+++ b/cli/transform.d.ts
@@ -3,9 +3,22 @@
  * @module cli/transform
  *//***/
 
-import { Parser } from "../src/parser";
+import { Parser } from "..";
+
+export abstract class Transform {
+
+  /** Base directory. */
+  readonly baseDir: string;
+
+  /** Writes a file to disk. */
+  writeFile(filename: string, contents: string | Uint8Array, baseDir: string): boolean;
+
+  /** Reads a file from disk. */
+  readFile(filename: string, baseDir: string): string | null;
+
+  /** Lists all files in a directory. */
+  listFiles(dirname: string, baseDir: string): string[] | null;
 
-export interface Transform {
   /** Called when parsing is complete, before a program is instantiated from the AST. */
-  afterParse(parser: Parser): void;
+  afterParse?(parser: Parser): void;
 }
diff --git a/cli/transform.js b/cli/transform.js
new file mode 100644
index 0000000000..dabbc389a1
--- /dev/null
+++ b/cli/transform.js
@@ -0,0 +1,5 @@
+class Transform {
+  // becomes replaced with the actual base by asc
+}
+
+exports.Transform = Transform;
diff --git a/examples/transform/assembly/index.ts b/examples/transform/assembly/index.ts
new file mode 100644
index 0000000000..8b1a393741
--- /dev/null
+++ b/examples/transform/assembly/index.ts
@@ -0,0 +1 @@
+// empty
diff --git a/examples/transform/mytransform.js b/examples/transform/mytransform.js
new file mode 100644
index 0000000000..958711f277
--- /dev/null
+++ b/examples/transform/mytransform.js
@@ -0,0 +1,12 @@
+const { Transform } = require("../../cli/transform"); // "assemblyscript/cli/transform"
+const { SourceKind } = require("../.."); // "assemblyscript"
+
+class MyTransform extends Transform {
+  afterParse(parser) {
+    console.error("afterParse called, baseDir = " + this.baseDir);
+    var sources = parser.program.sources;
+    sources.forEach(source => console.error("  " + source.internalPath + " [" + SourceKind[source.sourceKind] + "]"));
+  }
+}
+
+module.exports = MyTransform;
diff --git a/examples/transform/package.json b/examples/transform/package.json
new file mode 100644
index 0000000000..70229e6a6f
--- /dev/null
+++ b/examples/transform/package.json
@@ -0,0 +1,5 @@
+{
+  "scripts": {
+    "test": "asc assembly/index.ts --runtime none --transform mytransform.js"
+  }
+}

From b1fbbd54ba9717654b0ecf3298c2cb56c4afcc28 Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Thu, 10 Oct 2019 21:42:45 +0200
Subject: [PATCH 02/11] support TS transforms

---
 cli/asc.js                              | 36 +++++++++++++------------
 cli/transform.js                        |  7 ++---
 examples/transform/README.md            |  8 ++++++
 examples/transform/mytransform.js       |  2 +-
 examples/transform/mytransform.ts       | 12 +++++++++
 examples/transform/package.json         |  5 +++-
 examples/transform/ts/assembly/index.ts |  1 +
 examples/transform/ts/package.json      |  6 +++++
 8 files changed, 53 insertions(+), 24 deletions(-)
 create mode 100644 examples/transform/README.md
 create mode 100644 examples/transform/mytransform.ts
 create mode 100644 examples/transform/ts/assembly/index.ts
 create mode 100644 examples/transform/ts/package.json

diff --git a/cli/asc.js b/cli/asc.js
index 3af3137e92..88f81fb905 100644
--- a/cli/asc.js
+++ b/cli/asc.js
@@ -212,26 +212,28 @@ exports.main = function main(argv, options, callback) {
   // Set up transforms
   const transforms = [];
   if (args.transform) {
-    class Transform {
-      baseDir = baseDir;
-      writeFile = writeFile;
-      readFile = readFile;
-      listFiles = listFiles;
-    }
     args.transform.forEach(filename => {
-      const ctor = require(
-        path.isAbsolute(filename = filename.trim())
-          ? filename
-          : path.join(process.cwd(), filename)
-      );
-      let impl;
-      if (typeof ctor === "function") {
-        Object.setPrototypeOf(ctor, Transform);
-        impl = new ctor();
+      filename = path.isAbsolute(filename = filename.trim())
+        ? filename
+        : path.join(process.cwd(), filename);
+      let classOrModule;
+      if (/\.ts$/.test(filename)) {
+        require("ts-node").register({ transpileOnly: true, skipProject: true });
+        classOrModule = require(filename);
+      } else {
+        classOrModule = require(filename);
+      }
+      if (typeof classOrModule === "function") {
+        Object.defineProperties(classOrModule.prototype, {
+          baseDir: { value: baseDir },
+          readFile: { value: readFile },
+          writeFile: { value: writeFile },
+          listFiles: { value: listFiles }
+        });
+        transforms.push(new classOrModule());
       } else {
-        impl = ctor; // legacy module
+        transforms.push(classOrModule); // legacy module
       }
-      transforms.push(impl);
     });
   }
   function applyTransform(name, ...args) {
diff --git a/cli/transform.js b/cli/transform.js
index dabbc389a1..141277d2b6 100644
--- a/cli/transform.js
+++ b/cli/transform.js
@@ -1,5 +1,2 @@
-class Transform {
-  // becomes replaced with the actual base by asc
-}
-
-exports.Transform = Transform;
+// becomes replaced with the actual base by asc
+exports.Transform = function Transform() {};
diff --git a/examples/transform/README.md b/examples/transform/README.md
new file mode 100644
index 0000000000..52c7931349
--- /dev/null
+++ b/examples/transform/README.md
@@ -0,0 +1,8 @@
+Compiler transform examples
+===========================
+
+Both transforms written in JS and transforms written in TS can be used, with the
+latter requiring that the ts-node package is present.
+
+* [Example JavaScript transform](./mytransform.js)
+* [Example TypeScript transform](./mytransform.ts)
diff --git a/examples/transform/mytransform.js b/examples/transform/mytransform.js
index 958711f277..3978ebbaab 100644
--- a/examples/transform/mytransform.js
+++ b/examples/transform/mytransform.js
@@ -3,7 +3,7 @@ const { SourceKind } = require("../.."); // "assemblyscript"
 
 class MyTransform extends Transform {
   afterParse(parser) {
-    console.error("afterParse called, baseDir = " + this.baseDir);
+    console.error("[mytransform.js] afterParse called, baseDir = " + this.baseDir);
     var sources = parser.program.sources;
     sources.forEach(source => console.error("  " + source.internalPath + " [" + SourceKind[source.sourceKind] + "]"));
   }
diff --git a/examples/transform/mytransform.ts b/examples/transform/mytransform.ts
new file mode 100644
index 0000000000..6b0d8a61ec
--- /dev/null
+++ b/examples/transform/mytransform.ts
@@ -0,0 +1,12 @@
+import { Transform } from "../../cli/transform"; // "assemblyscript/cli/transform"
+import { Parser, SourceKind } from "../.."; // "assemblyscript"
+
+class MyTransform extends Transform {
+  afterParse(parser: Parser): void {
+    console.error("[mytransform.ts] afterParse called, baseDir = " + this.baseDir);
+    var sources = parser.program.sources;
+    sources.forEach(source => console.error("  " + source.internalPath + " [" + SourceKind[source.sourceKind] + "]"));
+  }
+}
+
+export = MyTransform;
diff --git a/examples/transform/package.json b/examples/transform/package.json
index 70229e6a6f..0c0d875507 100644
--- a/examples/transform/package.json
+++ b/examples/transform/package.json
@@ -1,5 +1,8 @@
 {
   "scripts": {
-    "test": "asc assembly/index.ts --runtime none --transform mytransform.js"
+    "test:js": "asc assembly/index.ts --runtime none --transform mytransform.js",
+    "test:ts": "asc assembly/index.ts --runtime none --transform mytransform.ts",
+    "test:multi": "asc assembly/index.ts --runtime none --transform mytransform.js --transform mytransform.ts",
+    "test": "npm run test:js && npm run test:ts && npm run test:multi"
   }
 }
diff --git a/examples/transform/ts/assembly/index.ts b/examples/transform/ts/assembly/index.ts
new file mode 100644
index 0000000000..8b1a393741
--- /dev/null
+++ b/examples/transform/ts/assembly/index.ts
@@ -0,0 +1 @@
+// empty
diff --git a/examples/transform/ts/package.json b/examples/transform/ts/package.json
new file mode 100644
index 0000000000..3b8eb06f68
--- /dev/null
+++ b/examples/transform/ts/package.json
@@ -0,0 +1,6 @@
+{
+  "scripts": {
+    "build": "tsc mytransform.ts",
+    "test": "asc assembly/index.ts --runtime none --transform mytransform.ts"
+  }
+}

From 5e760b0fee4105385df115142c728207bef2e9fd Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Thu, 10 Oct 2019 21:49:26 +0200
Subject: [PATCH 03/11] clean

---
 examples/transform/ts/assembly/index.ts | 1 -
 examples/transform/ts/package.json      | 6 ------
 2 files changed, 7 deletions(-)
 delete mode 100644 examples/transform/ts/assembly/index.ts
 delete mode 100644 examples/transform/ts/package.json

diff --git a/examples/transform/ts/assembly/index.ts b/examples/transform/ts/assembly/index.ts
deleted file mode 100644
index 8b1a393741..0000000000
--- a/examples/transform/ts/assembly/index.ts
+++ /dev/null
@@ -1 +0,0 @@
-// empty
diff --git a/examples/transform/ts/package.json b/examples/transform/ts/package.json
deleted file mode 100644
index 3b8eb06f68..0000000000
--- a/examples/transform/ts/package.json
+++ /dev/null
@@ -1,6 +0,0 @@
-{
-  "scripts": {
-    "build": "tsc mytransform.ts",
-    "test": "asc assembly/index.ts --runtime none --transform mytransform.ts"
-  }
-}

From cd5fe071d7ca86900d078afb497002a15b0da93b Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Thu, 10 Oct 2019 21:50:30 +0200
Subject: [PATCH 04/11] simpler

---
 cli/asc.js | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/cli/asc.js b/cli/asc.js
index 88f81fb905..f0612defec 100644
--- a/cli/asc.js
+++ b/cli/asc.js
@@ -219,10 +219,8 @@ exports.main = function main(argv, options, callback) {
       let classOrModule;
       if (/\.ts$/.test(filename)) {
         require("ts-node").register({ transpileOnly: true, skipProject: true });
-        classOrModule = require(filename);
-      } else {
-        classOrModule = require(filename);
       }
+      classOrModule = require(filename);
       if (typeof classOrModule === "function") {
         Object.defineProperties(classOrModule.prototype, {
           baseDir: { value: baseDir },

From e213c4ce4ddac3b86fc928c3268ee56dce86e21b Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Thu, 10 Oct 2019 21:51:08 +0200
Subject: [PATCH 05/11] even simpler

---
 cli/asc.js | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/cli/asc.js b/cli/asc.js
index f0612defec..7a5cfa62ba 100644
--- a/cli/asc.js
+++ b/cli/asc.js
@@ -216,11 +216,8 @@ exports.main = function main(argv, options, callback) {
       filename = path.isAbsolute(filename = filename.trim())
         ? filename
         : path.join(process.cwd(), filename);
-      let classOrModule;
-      if (/\.ts$/.test(filename)) {
-        require("ts-node").register({ transpileOnly: true, skipProject: true });
-      }
-      classOrModule = require(filename);
+      if (/\.ts$/.test(filename)) require("ts-node").register({ transpileOnly: true, skipProject: true });
+      const classOrModule = require(filename);
       if (typeof classOrModule === "function") {
         Object.defineProperties(classOrModule.prototype, {
           baseDir: { value: baseDir },

From 83c24129d00e244752b16702bbb503d2041639f9 Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Sat, 12 Oct 2019 17:44:00 +0200
Subject: [PATCH 06/11] implement suggestions

---
 cli/asc.js                        | 13 ++++++++-----
 cli/transform.d.ts                | 10 ++++++++++
 examples/transform/mytransform.js |  4 ++--
 examples/transform/mytransform.ts |  4 ++--
 4 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/cli/asc.js b/cli/asc.js
index 7a5cfa62ba..ca2ab4a3e6 100644
--- a/cli/asc.js
+++ b/cli/asc.js
@@ -219,11 +219,14 @@ exports.main = function main(argv, options, callback) {
       if (/\.ts$/.test(filename)) require("ts-node").register({ transpileOnly: true, skipProject: true });
       const classOrModule = require(filename);
       if (typeof classOrModule === "function") {
-        Object.defineProperties(classOrModule.prototype, {
-          baseDir: { value: baseDir },
-          readFile: { value: readFile },
-          writeFile: { value: writeFile },
-          listFiles: { value: listFiles }
+        Object.assign(classOrModule.prototype, {
+          baseDir,
+          stdout,
+          stderr,
+          log: console.error || console.log,
+          readFile,
+          writeFile,
+          listFiles
         });
         transforms.push(new classOrModule());
       } else {
diff --git a/cli/transform.d.ts b/cli/transform.d.ts
index 82085bf878..3aabeff86a 100644
--- a/cli/transform.d.ts
+++ b/cli/transform.d.ts
@@ -4,12 +4,22 @@
  *//***/
 
 import { Parser } from "..";
+import { OutputStream } from "./asc";
 
 export abstract class Transform {
 
   /** Base directory. */
   readonly baseDir: string;
 
+  /** Output stream used by the compiler. */
+  readonly stdout: OutputStream;
+
+  /** Error stream used by the compiler. */
+  readonly stderr: OutputStream;
+
+  /** Logs a message to console. */
+  readonly log: typeof console.log;
+
   /** Writes a file to disk. */
   writeFile(filename: string, contents: string | Uint8Array, baseDir: string): boolean;
 
diff --git a/examples/transform/mytransform.js b/examples/transform/mytransform.js
index 3978ebbaab..40ec2d933c 100644
--- a/examples/transform/mytransform.js
+++ b/examples/transform/mytransform.js
@@ -3,9 +3,9 @@ const { SourceKind } = require("../.."); // "assemblyscript"
 
 class MyTransform extends Transform {
   afterParse(parser) {
-    console.error("[mytransform.js] afterParse called, baseDir = " + this.baseDir);
+    this.log("[mytransform.js] afterParse called, baseDir = " + this.baseDir);
     var sources = parser.program.sources;
-    sources.forEach(source => console.error("  " + source.internalPath + " [" + SourceKind[source.sourceKind] + "]"));
+    sources.forEach(source => this.log("  " + source.internalPath + " [" + SourceKind[source.sourceKind] + "]"));
   }
 }
 
diff --git a/examples/transform/mytransform.ts b/examples/transform/mytransform.ts
index 6b0d8a61ec..23181f3c11 100644
--- a/examples/transform/mytransform.ts
+++ b/examples/transform/mytransform.ts
@@ -3,9 +3,9 @@ import { Parser, SourceKind } from "../.."; // "assemblyscript"
 
 class MyTransform extends Transform {
   afterParse(parser: Parser): void {
-    console.error("[mytransform.ts] afterParse called, baseDir = " + this.baseDir);
+    this.log("[mytransform.ts] afterParse called, baseDir = " + this.baseDir);
     var sources = parser.program.sources;
-    sources.forEach(source => console.error("  " + source.internalPath + " [" + SourceKind[source.sourceKind] + "]"));
+    sources.forEach(source => this.log("  " + source.internalPath + " [" + SourceKind[source.sourceKind] + "]"));
   }
 }
 

From c8d4531ec5b2f53c414f115ff504c28c9e7507b0 Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Sat, 12 Oct 2019 18:01:19 +0200
Subject: [PATCH 07/11] fix historical IE paranoia

---
 cli/asc.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cli/asc.js b/cli/asc.js
index ca2ab4a3e6..07f999db7c 100644
--- a/cli/asc.js
+++ b/cli/asc.js
@@ -223,7 +223,7 @@ exports.main = function main(argv, options, callback) {
           baseDir,
           stdout,
           stderr,
-          log: console.error || console.log,
+          log: console.error,
           readFile,
           writeFile,
           listFiles

From d0647d4c303f30c2a4bb24b5acdb6b91317d067b Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Sat, 12 Oct 2019 23:16:29 +0200
Subject: [PATCH 08/11] postprocess assemblyscript.d.ts

---
 scripts/build-dts.js | 88 ++++++++++++++++++++++++++++++--------------
 1 file changed, 61 insertions(+), 27 deletions(-)

diff --git a/scripts/build-dts.js b/scripts/build-dts.js
index 7f9de26678..006dc3e62b 100644
--- a/scripts/build-dts.js
+++ b/scripts/build-dts.js
@@ -408,41 +408,40 @@
     exports.default = generate;
 });
 
-const prelude = `declare type bool = boolean;
-declare type i8 = number;
-declare type i16 = number;
-declare type i32 = number;
-declare type isize = number;
-declare type u8 = number;
-declare type u16 = number;
-declare type u32 = number;
-declare type usize = number;
-declare type f32 = number;
-declare type f64 = number;
-declare module 'assemblyscript' {
-  export * from 'assemblyscript/src/index';
+const path = require("path");
+const fs = require("fs");
+const stream = require("stream");
+const util = require("util");
+
+function OutputStream(options) {
+    stream.Writable.call(this, options);
+    this.chunks = [];
 }
-`;
+util.inherits(OutputStream, stream.Writable);
+OutputStream.prototype._write = function(chunk, enc, cb) {
+    this.chunks.push(chunk);
+    cb();
+};
+OutputStream.prototype.toBuffer = function() {
+    return Buffer.concat(this.chunks);
+};
+OutputStream.prototype.toString = function() {
+    return this.toBuffer().toString("utf8");
+};
 
-var path = require("path");
-var fs = require("fs");
-var stdout = fs.createWriteStream(path.resolve(__dirname, "..", "dist", "assemblyscript.d.ts"));
-stdout.write(prelude);
-stdout.write = (function(_write) {
-    return function(...args) {
-        if (typeof args[0] === "string") {
-            args[0] = args[0].replace(/\/\/\/ <reference[^>]*>\r?\n/g, "");
-        }
-        return _write.apply(stdout, args);
-    };
-})(stdout.write);
+const stdout = new OutputStream();
+stdout.write(`declare module 'assemblyscript' {
+    export * from 'assemblyscript/src/index';
+}
+`);
 
 module.exports.default({
     project: path.resolve(__dirname, "..", "src"),
     prefix: "assemblyscript",
     exclude: [
         "glue/js/index.ts",
-        "glue/js/node.d.ts"
+        "glue/js/node.d.ts",
+        "glue/binaryen.d.ts"
     ],
     verbose: true,
     sendMessage: console.log,
@@ -459,3 +458,38 @@ module.exports.default({
     sendMessage: console.log,
     stdout: stdout
 });
+
+var source = stdout.toString().replace(/\/\/\/ <reference[^>]*>\r?\n/g, "");
+
+const ts = require("typescript");
+const sourceFile = ts.createSourceFile("assemblyscript.d.ts", source, ts.ScriptTarget.ESNext, false, ts.ScriptKind.TS);
+
+console.log("transforming:");
+var numReplaced = 0;
+const result = ts.transform(sourceFile, [
+    function(context) {
+        const visit = node => {
+            node = ts.visitEachChild(node, visit, context);
+            if (ts.isTypeNode(node)) {
+                const name = node.getText(sourceFile);
+                switch (name) {
+                    // this is wrong, but works
+                    case "bool": ++numReplaced; return ts.createIdentifier("boolean");
+                    default: if (!/^(?:Binaryen|Relooper)/.test(name)) break;
+                    case "i8": case "i16": case "i32": case "isize":
+                    case "u8": case "u16": case "u32": case "usize":
+                    case "f32": case "f64": ++numReplaced; return ts.createIdentifier("number");
+                }
+            }
+            return node;
+        };
+        return node => ts.visitNode(node, visit);
+    }
+]);
+console.log("  replaced " + numReplaced + " AS types with JS types");
+
+fs.writeFileSync(
+    path.resolve(__dirname, "..", "dist", "assemblyscript.d.ts"),
+    ts.createPrinter().printFile(result.transformed[0]),
+    "utf8"
+);

From d18231a1443f63764b7c395c7afbd3b076bfe3db Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Tue, 15 Oct 2019 12:35:38 +0200
Subject: [PATCH 09/11] add afterCompile hook

---
 cli/asc.js                        | 3 +++
 cli/transform.d.ts                | 5 ++++-
 examples/transform/mytransform.js | 6 ++++++
 examples/transform/mytransform.ts | 8 +++++++-
 4 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/cli/asc.js b/cli/asc.js
index 07f999db7c..6dfc7fa56f 100644
--- a/cli/asc.js
+++ b/cli/asc.js
@@ -542,6 +542,9 @@ exports.main = function main(argv, options, callback) {
     return callback(Error("Compile error"));
   }
 
+  // Call afterCompile transform hook
+  applyTransform("afterCompile", module);
+
   // Validate the module if requested
   if (args.validate) {
     stats.validateCount++;
diff --git a/cli/transform.d.ts b/cli/transform.d.ts
index 3aabeff86a..a1aff852fc 100644
--- a/cli/transform.d.ts
+++ b/cli/transform.d.ts
@@ -3,7 +3,7 @@
  * @module cli/transform
  *//***/
 
-import { Parser } from "..";
+import { Parser, Module } from "..";
 import { OutputStream } from "./asc";
 
 export abstract class Transform {
@@ -31,4 +31,7 @@ export abstract class Transform {
 
   /** Called when parsing is complete, before a program is instantiated from the AST. */
   afterParse?(parser: Parser): void;
+
+  /** Called when compilation is complete, before the module is being validated. */
+  afterCompile?(module: Module): void;
 }
diff --git a/examples/transform/mytransform.js b/examples/transform/mytransform.js
index 40ec2d933c..e903ec0626 100644
--- a/examples/transform/mytransform.js
+++ b/examples/transform/mytransform.js
@@ -1,5 +1,6 @@
 const { Transform } = require("../../cli/transform"); // "assemblyscript/cli/transform"
 const { SourceKind } = require("../.."); // "assemblyscript"
+const binaryen = require("binaryen");
 
 class MyTransform extends Transform {
   afterParse(parser) {
@@ -7,6 +8,11 @@ class MyTransform extends Transform {
     var sources = parser.program.sources;
     sources.forEach(source => this.log("  " + source.internalPath + " [" + SourceKind[source.sourceKind] + "]"));
   }
+  afterCompile(asModule) {
+    this.log("[mytransform.js] afterCompile called");
+    var module = binaryen.wrapModule(asModule.ref);
+    this.log(module.emitBinary());
+  }
 }
 
 module.exports = MyTransform;
diff --git a/examples/transform/mytransform.ts b/examples/transform/mytransform.ts
index 23181f3c11..18fd7e36be 100644
--- a/examples/transform/mytransform.ts
+++ b/examples/transform/mytransform.ts
@@ -1,5 +1,6 @@
 import { Transform } from "../../cli/transform"; // "assemblyscript/cli/transform"
-import { Parser, SourceKind } from "../.."; // "assemblyscript"
+import { Parser, Module, SourceKind } from "../.."; // "assemblyscript"
+import * as binaryen from "binaryen";
 
 class MyTransform extends Transform {
   afterParse(parser: Parser): void {
@@ -7,6 +8,11 @@ class MyTransform extends Transform {
     var sources = parser.program.sources;
     sources.forEach(source => this.log("  " + source.internalPath + " [" + SourceKind[source.sourceKind] + "]"));
   }
+  afterCompile(asModule: Module): void {
+    this.log("[mytransform.ts] afterCompile called");
+    var module = binaryen.wrapModule(asModule.ref);
+    this.log(module.emitBinary());
+  }
 }
 
 export = MyTransform;

From ba613cb0ae0211cc3acce40f83cdeaa3e246a823 Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Wed, 16 Oct 2019 10:44:50 +0200
Subject: [PATCH 10/11] propagate errors to callback

---
 cli/asc.js | 23 ++++++++++++++++++-----
 1 file changed, 18 insertions(+), 5 deletions(-)

diff --git a/cli/asc.js b/cli/asc.js
index 6dfc7fa56f..65e46f8482 100644
--- a/cli/asc.js
+++ b/cli/asc.js
@@ -235,9 +235,16 @@ exports.main = function main(argv, options, callback) {
     });
   }
   function applyTransform(name, ...args) {
-    transforms.forEach(transform => {
-      if (typeof transform[name] === "function") transform[name](...args);
-    });
+    for (let i = 0, k = transforms.length; i < k; ++i) {
+      let transform = transforms[i];
+      if (typeof transform[name] === "function") {
+        try {
+          transform[name](...args);
+        } catch (e) {
+          return e;
+        }
+      }
+    }
   }
 
   // Begin parsing
@@ -438,7 +445,10 @@ exports.main = function main(argv, options, callback) {
   }
 
   // Call afterParse transform hook
-  applyTransform("afterParse", parser);
+  {
+    let error = applyTransform("afterParse", parser);
+    if (error) return callback(error);
+  }
 
   // Parse additional files, if any
   {
@@ -543,7 +553,10 @@ exports.main = function main(argv, options, callback) {
   }
 
   // Call afterCompile transform hook
-  applyTransform("afterCompile", module);
+  {
+    let error = applyTransform("afterCompile", module);
+    if (error) return callback(error);
+  }
 
   // Validate the module if requested
   if (args.validate) {

From f45544a430e373265d407a39e432ff91208dd35a Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Wed, 16 Oct 2019 12:32:48 +0200
Subject: [PATCH 11/11] also handle errors when loading transforms

---
 cli/asc.js | 38 ++++++++++++++++++++++----------------
 1 file changed, 22 insertions(+), 16 deletions(-)

diff --git a/cli/asc.js b/cli/asc.js
index 65e46f8482..6fd5a61925 100644
--- a/cli/asc.js
+++ b/cli/asc.js
@@ -212,27 +212,33 @@ exports.main = function main(argv, options, callback) {
   // Set up transforms
   const transforms = [];
   if (args.transform) {
-    args.transform.forEach(filename => {
+    let transformArgs = args.transform;
+    for (let i = 0, k = transformArgs.length; i < k; ++i) {
+      let filename = transformArgs[i];
       filename = path.isAbsolute(filename = filename.trim())
         ? filename
         : path.join(process.cwd(), filename);
       if (/\.ts$/.test(filename)) require("ts-node").register({ transpileOnly: true, skipProject: true });
-      const classOrModule = require(filename);
-      if (typeof classOrModule === "function") {
-        Object.assign(classOrModule.prototype, {
-          baseDir,
-          stdout,
-          stderr,
-          log: console.error,
-          readFile,
-          writeFile,
-          listFiles
-        });
-        transforms.push(new classOrModule());
-      } else {
-        transforms.push(classOrModule); // legacy module
+      try {
+        const classOrModule = require(filename);
+        if (typeof classOrModule === "function") {
+          Object.assign(classOrModule.prototype, {
+            baseDir,
+            stdout,
+            stderr,
+            log: console.error,
+            readFile,
+            writeFile,
+            listFiles
+          });
+          transforms.push(new classOrModule());
+        } else {
+          transforms.push(classOrModule); // legacy module
+        }
+      } catch (e) {
+        return callback(e);
       }
-    });
+    }
   }
   function applyTransform(name, ...args) {
     for (let i = 0, k = transforms.length; i < k; ++i) {