fix: keep space in `<pre>` or `preserveWhitespace: true`

src/compiler/compile/nodes/Text.ts

@@ -43,4 +43,21 @@ export default class Text extends Node {
 
 		return parent_element.namespace || elements_without_text.has(parent_element.name);
 	}
+
+	keep_space(): boolean {
+		if (this.component.component_options.preserveWhitespace) return true;
+		return this.within_pre();
+	}
+
+	within_pre(): boolean {
+		let node = this.parent;
+		while (node) {
+			if (node.type === 'Element' && node.name === 'pre') {
+				return true;
+			}
+			node = node.parent;
+		}
+
+		return false;
+	}
 }

src/compiler/compile/render_dom/wrappers/Fragment.ts

@@ -95,7 +95,7 @@ export default class FragmentWrapper {
 						next_sibling ? (next_sibling.node.type === 'Text' && /^\s/.test(next_sibling.node.data) && trimmable_at(child, next_sibling)) : !child.has_ancestor('EachBlock')
 					);
 
-					if (should_trim) {
+					if (should_trim && !child.keep_space()) {
 						data = trim_end(data);
 						if (!data) continue;
 					}
@@ -127,7 +127,7 @@ export default class FragmentWrapper {
 		if (strip_whitespace) {
 			const first = this.nodes[0] as Text;
 
-			if (first && first.node.type === 'Text') {
+			if (first && first.node.type === 'Text' && !first.node.keep_space()) {
 				first.data = trim_start(first.data);
 				if (!first.data) {
 					first.var = null;

src/compiler/compile/render_dom/wrappers/Text.ts

@@ -29,15 +29,7 @@ export default class TextWrapper extends Wrapper {
 		if (this.renderer.component.component_options.preserveWhitespace) return false;
 		if (/[\S\u00A0]/.test(this.data)) return false;
 
-		let node = this.parent && this.parent.node;
-		while (node) {
-			if (node.type === 'Element' && node.name === 'pre') {
-				return false;
-			}
-			node = node.parent;
-		}
-
-		return true;
+		return !this.node.within_pre();
 	}
 
 	render(block: Block, parent_node: Identifier, parent_nodes: Identifier) {

src/compiler/compile/render_ssr/handlers/utils/remove_whitespace_children.ts

@@ -26,7 +26,7 @@ export default function remove_whitespace_children(children: INode[], next?: INo
 					  trimmable_at(child, next)
 					: !child.has_ancestor('EachBlock');
 
-				if (should_trim) {
+				if (should_trim && !child.keep_space()) {
 					data = trim_end(data);
 					if (!data) continue;
 				}
@@ -47,7 +47,7 @@ export default function remove_whitespace_children(children: INode[], next?: INo
 	}
 
 	const first = nodes[0];
-	if (first && first.type === 'Text') {
+	if (first && first.type === 'Text' && !first.keep_space()) {
 		first.data = trim_start(first.data);
 		if (!first.data) {
 			first.var = null;

test/js/samples/pre-tag/expected.js

@@ -0,0 +1,86 @@
+/* generated by Svelte vX.Y.Z */
+import {
+	SvelteComponent,
+	detach,
+	element,
+	init,
+	insert,
+	noop,
+	safe_not_equal,
+	space
+} from "svelte/internal";
+
+function create_fragment(ctx) {
+	let pre0;
+	let t3;
+	let div0;
+	let t7;
+	let div1;
+
+	return {
+		c() {
+			pre0 = element("pre");
+
+			pre0.innerHTML = `
+  A
+  B
+  <span>
+    C
+    D
+  </span>
+  E
+  F
+`;
+
+			t3 = space();
+			div0 = element("div");
+
+			div0.innerHTML = `A
+  B
+  <span>C
+    D</span>
+  E
+  F`;
+
+			t7 = space();
+			div1 = element("div");
+
+			div1.innerHTML = `<pre>
+    A
+    B
+    <span>
+      C
+      D
+    </span>
+    E
+    F
+  </pre>`;
+		},
+		m(target, anchor) {
+			insert(target, pre0, anchor);
+			insert(target, t3, anchor);
+			insert(target, div0, anchor);
+			insert(target, t7, anchor);
+			insert(target, div1, anchor);
+		},
+		p: noop,
+		i: noop,
+		o: noop,
+		d(detaching) {
+			if (detaching) detach(pre0);
+			if (detaching) detach(t3);
+			if (detaching) detach(div0);
+			if (detaching) detach(t7);
+			if (detaching) detach(div1);
+		}
+	};
+}
+
+class Component extends SvelteComponent {
+	constructor(options) {
+		super();
+		init(this, options, null, create_fragment, safe_not_equal, {});
+	}
+}
+
+export default Component;

test/js/samples/pre-tag/input.svelte

@@ -0,0 +1,34 @@
+<pre>
+  A
+  B
+  <span>
+    C
+    D
+  </span>
+  E
+  F
+</pre>
+
+<div>
+  A
+  B
+  <span>
+    C
+    D
+  </span>
+  E
+  F
+</div>
+
+<div>
+  <pre>
+    A
+    B
+    <span>
+      C
+      D
+    </span>
+    E
+    F
+  </pre>
+</div>

test/js/samples/preserve-whitespaces/_config.js

@@ -0,0 +1,5 @@
+export default {
+	options: {
+		preserveWhitespace: true
+	}
+};

test/js/samples/preserve-whitespaces/expected.js

@@ -0,0 +1,92 @@
+/* generated by Svelte vX.Y.Z */
+import {
+	SvelteComponent,
+	detach,
+	element,
+	init,
+	insert,
+	noop,
+	safe_not_equal,
+	text
+} from "svelte/internal";
+
+function create_fragment(ctx) {
+	let pre0;
+	let t3;
+	let div0;
+	let t7;
+	let div1;
+
+	return {
+		c() {
+			pre0 = element("pre");
+
+			pre0.innerHTML = `
+  A
+  B
+  <span>
+    C
+    D
+  </span>
+  E
+  F
+`;
+
+			t3 = text("\n\n");
+			div0 = element("div");
+
+			div0.innerHTML = `
+  A
+  B
+  <span>
+    C
+    D
+  </span>
+  E
+  F
+`;
+
+			t7 = text("\n\n");
+			div1 = element("div");
+
+			div1.innerHTML = `
+  <pre>
+    A
+    B
+    <span>
+      C
+      D
+    </span>
+    E
+    F
+  </pre>
+`;
+		},
+		m(target, anchor) {
+			insert(target, pre0, anchor);
+			insert(target, t3, anchor);
+			insert(target, div0, anchor);
+			insert(target, t7, anchor);
+			insert(target, div1, anchor);
+		},
+		p: noop,
+		i: noop,
+		o: noop,
+		d(detaching) {
+			if (detaching) detach(pre0);
+			if (detaching) detach(t3);
+			if (detaching) detach(div0);
+			if (detaching) detach(t7);
+			if (detaching) detach(div1);
+		}
+	};
+}
+
+class Component extends SvelteComponent {
+	constructor(options) {
+		super();
+		init(this, options, null, create_fragment, safe_not_equal, {});
+	}
+}
+
+export default Component;

test/js/samples/preserve-whitespaces/input.svelte

@@ -0,0 +1,34 @@
+<pre>
+  A
+  B
+  <span>
+    C
+    D
+  </span>
+  E
+  F
+</pre>
+
+<div>
+  A
+  B
+  <span>
+    C
+    D
+  </span>
+  E
+  F
+</div>
+
+<div>
+  <pre>
+    A
+    B
+    <span>
+      C
+      D
+    </span>
+    E
+    F
+  </pre>
+</div>

test/server-side-rendering/index.ts

@@ -83,9 +83,13 @@ describe('ssr', () => {
 				if (css.code) fs.writeFileSync(`${dir}/_actual.css`, css.code);
 
 				try {
-					(compileOptions.preserveComments
-						? assert.htmlEqualWithComments
-						: assert.htmlEqual)(html, expectedHtml);
+					if (config.withoutNormalizeHtml) {
+						assert.strictEqual(html.trim(), expectedHtml.trim());
+					} else {
+						(compileOptions.preserveComments
+							? assert.htmlEqualWithComments
+							: assert.htmlEqual)(html, expectedHtml);
+					}
 				} catch (error) {
 					if (shouldUpdateExpected()) {
 						fs.writeFileSync(`${dir}/_expected.html`, html);

test/server-side-rendering/samples/pre-tag/_config.js

@@ -0,0 +1,3 @@
+export default {
+	withoutNormalizeHtml: true
+};

test/server-side-rendering/samples/pre-tag/_expected.html

@@ -0,0 +1,30 @@
+<pre>
+  A
+  B
+  <span>
+    C
+    D
+  </span>
+  E
+  F
+</pre>
+
+<div>A
+  B
+  <span>C
+    D
+  </span>
+  E
+  F
+</div>
+
+<div><pre>
+    A
+    B
+    <span>
+      C
+      D
+    </span>
+    E
+    F
+  </pre></div>

test/server-side-rendering/samples/pre-tag/main.svelte

@@ -0,0 +1,34 @@
+<pre>
+  A
+  B
+  <span>
+    C
+    D
+  </span>
+  E
+  F
+</pre>
+
+<div>
+  A
+  B
+  <span>
+    C
+    D
+  </span>
+  E
+  F
+</div>
+
+<div>
+  <pre>
+    A
+    B
+    <span>
+      C
+      D
+    </span>
+    E
+    F
+  </pre>
+</div>

test/server-side-rendering/samples/preserve-whitespaces/_config.js

@@ -0,0 +1,6 @@
+export default {
+	withoutNormalizeHtml: true,
+	compileOptions: {
+		preserveWhitespace: true
+	}
+};

test/server-side-rendering/samples/preserve-whitespaces/_expected.html

@@ -0,0 +1,34 @@
+<pre>
+  A
+  B
+  <span>
+    C
+    D
+  </span>
+  E
+  F
+</pre>
+
+<div>
+  A
+  B
+  <span>
+    C
+    D
+  </span>
+  E
+  F
+</div>
+
+<div>
+  <pre>
+    A
+    B
+    <span>
+      C
+      D
+    </span>
+    E
+    F
+  </pre>
+</div>

test/server-side-rendering/samples/preserve-whitespaces/main.svelte

@@ -0,0 +1,34 @@
+<pre>
+  A
+  B
+  <span>
+    C
+    D
+  </span>
+  E
+  F
+</pre>
+
+<div>
+  A
+  B
+  <span>
+    C
+    D
+  </span>
+  E
+  F
+</div>
+
+<div>
+  <pre>
+    A
+    B
+    <span>
+      C
+      D
+    </span>
+    E
+    F
+  </pre>
+</div>