Merge pull request #46 from smartcontractkit/imports

Author: KuphJr

.changeset/pretty-countries-look.md

@@ -0,0 +1,5 @@
+---
+'@chainlink/functions-toolkit': patch
+---
+
+Added support for 3rd party imports in the simulator

README.md

@@ -572,6 +572,17 @@ const result = await simulateScript({
 }
 ```
 
+Any 3rd party imports used in the JavaScript source code are loaded asynchronously at runtime. Therefore, to use 3rd party imports in the source code that is executed by the `simulateScript` function, you must use the async `import` function as shown in the examples below.
+
+```
+const { format } = await import("npm:date-fns");
+return Functions.encodeString(format(new Date(), "yyyy-MM-dd"));
+```
+```
+const { escape } = await import("https://deno.land/std/regexp/mod.ts");
+return Functions.encodeString(escape("$hello*world?"));
+```
+
 **_NOTE:_** When running `simulateScript`, depending on your security settings, you may get a popup asking if you would like to accept incoming network connections. You can safely accept or ignore this popup and it should disappear when the simulation is complete.
 
 **_NOTE:_** The `simulateScript` function is a debugging tool and hence is not a perfect representation of the actual Chainlink oracle execution environment. Therefore, it is important to make a Functions request on a supported testnet blockchain before mainnet usage.

src/simulateScript/simulateScript.ts

@@ -86,8 +86,6 @@ export const simulateScript = async ({
   const simulation = spawn('deno', [
     'run',
     '--no-prompt',
-    '--no-npm',
-    '--no-remote',
     `--v8-flags=--max-old-space-size=${maxMemoryUsageMb}`,
     '--allow-net',
     scriptPath,

test/unit/simulateScript.test.ts

@@ -207,21 +207,6 @@ describe('simulateScript', () => {
       expect(result).toEqual(expected)
     })
 
-    it('should capture import error', async () => {
-      const result = await simulateScript({
-        source: 'const http = await import("https://deno.land/std/http/mod.ts");',
-        maxExecutionTimeMs: 100,
-      })
-
-      const expected = {
-        capturedTerminalOutput: '',
-        errorString:
-          'A remote specifier was requested: "https://deno.land/std/http/mod.ts", but --no-remote is specified.',
-      }
-
-      expect(result).toEqual(expected)
-    })
-
     it('should capture permissions error', async () => {
       const result = await simulateScript({
         source: "Deno.openSync('test.txt')",
@@ -296,6 +281,28 @@ describe('simulateScript', () => {
 
       await expect(result).rejects.toThrow('bytesArgs param contains invalid hex string')
     })
+
+    it('should allow 3rd party imports', async () => {
+      const result = await simulateScript({
+        source:
+          'const { escape } = await import("https://deno.land/std/regexp/mod.ts"); return Functions.encodeString(escape("$hello*world?"));',
+      })
+
+      expect(result.responseBytesHexstring).toEqual(
+        `0x${Buffer.from('\\$hello\\*world\\?').toString('hex')}`,
+      )
+    })
+
+    it('should allow NPM imports', async () => {
+      const result = await simulateScript({
+        source:
+          'const { format } = await import("npm:date-fns"); return Functions.encodeString(format(new Date(), "yyyy-MM-dd"));',
+      })
+
+      expect(Buffer.from(result.responseBytesHexstring?.slice(2) as string, 'hex').length).toEqual(
+        10,
+      )
+    })
   })
 })