fix: export w/ curly brace on next line, extra curly brace before def (#1075)

Author: alex-snezhko

.changeset/fast-lemons-pay.md

@@ -0,0 +1,5 @@
+---
+"@astrojs/compiler": patch
+---
+
+Improves detection of function body opening curly brace for exported functions.

internal/js_scanner/js_scanner.go

@@ -80,8 +80,10 @@ outer:
 		// a specifier is found, and a line terminator has been found
 		if token == js.ExportToken {
 			flags := make(map[string]bool)
+			tokensFound := make(map[string]bool)
 			foundIdent := false
 			foundSemicolonOrLineTerminator := false
+			foundBody := false
 			start := i
 			i += len(value)
 			for {
@@ -94,6 +96,7 @@ outer:
 				}
 				i += len(nextValue)
 				flags[string(nextValue)] = true
+				tokensFound[string(nextValue)] = true
 
 				if next == js.ErrorToken && l.Err() == io.EOF {
 					foundSemicolonOrLineTerminator = true
@@ -113,7 +116,7 @@ outer:
 					if next == js.LineTerminatorToken && i < len(source) && (source[i] == '&' || source[i] == '|') {
 						continue
 					}
-					if (flags["function"] || flags["=>"] || flags["interface"]) && !flags["{"] {
+					if (flags["function"] || flags["=>"] || flags["interface"]) && !foundBody {
 						continue
 					}
 					if flags["&"] || flags["="] {
@@ -125,6 +128,17 @@ outer:
 
 					foundSemicolonOrLineTerminator = true
 				} else if js.IsPunctuator(next) {
+					if nextValue[0] == '{' {
+						if flags["function"] {
+							// Curly braces can occur in a function parameter destructuring, which we don't want to consider
+							foundBody = foundBody || pairs['('] == 0
+						} else if flags["=>"] {
+							// Arrow can also occur in type definition before arrow function body (which we don't want to consider), but `=` cannot
+							foundBody = foundBody || tokensFound["="]
+						} else {
+							foundBody = true
+						}
+					}
 					if nextValue[0] == '{' || nextValue[0] == '(' || nextValue[0] == '[' {
 						flags[string(nextValue[0])] = true
 						pairs[nextValue[0]]++

internal/js_scanner/js_scanner_test.go

@@ -260,6 +260,116 @@ export async function getStaticPaths() {
 const b = await fetch()`,
 			want: `export async function getStaticPaths() {
 	const content = Astro.fetchContent('**/*.md');
+}`,
+		},
+		{
+			name: "getStaticPaths with curly brace on next line and destructured props",
+			source: `import { fn } from "package";
+export async function getStaticPaths({ paginate })
+{
+	const content = Astro.fetchContent('**/*.md');
+}
+const b = await fetch()`,
+			want: `export async function getStaticPaths({ paginate })
+{
+	const content = Astro.fetchContent('**/*.md');
+}`,
+		},
+		{
+			name: "getStaticPaths with curly brace on next line and param definition type in curly braces",
+			source: `import { fn } from "package";
+export async function getStaticPaths(input: { paginate: any })
+{
+	const content = Astro.fetchContent('**/*.md');
+}
+const b = await fetch()`,
+			want: `export async function getStaticPaths(input: { paginate: any })
+{
+	const content = Astro.fetchContent('**/*.md');
+}`,
+		},
+		{
+			name: "getStaticPaths with curly brace on next line and param definition type in square braces",
+			source: `import { fn } from "package";
+export async function getStaticPaths([{ stuff }])
+{
+	const content = Astro.fetchContent('**/*.md');
+}
+const b = await fetch()`,
+			want: `export async function getStaticPaths([{ stuff }])
+{
+	const content = Astro.fetchContent('**/*.md');
+}`,
+		},
+		{
+			name: "getStaticPaths with curly brace on next line and type specified with square braces 1",
+			source: `import { fn } from "package";
+export const getStaticPaths: () => { params: any }[]
+= () =>
+{
+	const content = Astro.fetchContent('**/*.md');
+}
+const b = await fetch()`,
+			want: `export const getStaticPaths: () => { params: any }[]
+= () =>
+{
+	const content = Astro.fetchContent('**/*.md');
+}`,
+		},
+		{
+			name: "getStaticPaths with curly brace on next line and type specified with square braces 2",
+			source: `import { fn } from "package";
+export const getStaticPaths: () => { params: any }[] =
+() =>
+{
+	const content = Astro.fetchContent('**/*.md');
+}
+const b = await fetch()`,
+			want: `export const getStaticPaths: () => { params: any }[] =
+() =>
+{
+	const content = Astro.fetchContent('**/*.md');
+}`,
+		},
+		{
+			name: "getStaticPaths with curly brace on next line and type specified with square braces 3",
+			source: `import { fn } from "package";
+export const getStaticPaths: () => { params: any }[] = ()
+=>
+{
+	const content = Astro.fetchContent('**/*.md');
+}
+const b = await fetch()`,
+			want: `export const getStaticPaths: () => { params: any }[] = ()
+=>
+{
+	const content = Astro.fetchContent('**/*.md');
+}`,
+		},
+		{
+			name: "getStaticPaths with curly brace on next line and type specified with square braces 4",
+			source: `import { fn } from "package";
+export const getStaticPaths: () => { params: any }[] = () =>
+{
+	const content = Astro.fetchContent('**/*.md');
+}
+const b = await fetch()`,
+			want: `export const getStaticPaths: () => { params: any }[] = () =>
+{
+	const content = Astro.fetchContent('**/*.md');
+}`,
+		},
+		{
+			name: "getStaticPaths with curly brace on next line and definition specified by anonymous function with destructured parameter",
+			source: `import { fn } from "package";
+export const getStaticPaths = function({ paginate })
+{
+	const content = Astro.fetchContent('**/*.md');
+}
+const b = await fetch()`,
+			want: `export const getStaticPaths = function({ paginate })
+{
+	const content = Astro.fetchContent('**/*.md');
 }`,
 		},
 		{

packages/compiler/test/basic/get-static-paths.ts

@@ -25,6 +25,29 @@ export async function getStaticPaths()
 	);
 });
 
+test('getStaticPaths with braces on newline and destructured params', async () => {
+	const FIXTURE = `---
+import A from './A.astro';
+export async function getStaticPaths({ paginate })
+{
+  return [
+    { params: { id: '1' } },
+    { params: { id: '2' } },
+    { params: { id: '3' } }
+  ];
+}
+---
+
+<div></div>
+`;
+	const result = await transform(FIXTURE);
+	assert.match(
+		result.code,
+		'export async function getStaticPaths({ paginate })\n{',
+		'Expected output to contain getStaticPaths output'
+	);
+});
+
 test('getStaticPaths as const without braces', async () => {
 	const FIXTURE = `---
 import A from './A.astro';