From 40f4aeff5539e97ca9124fa33dd0deb70c75f90a Mon Sep 17 00:00:00 2001
From: Quentin Chateau <quentin.chateau@gmail.com>
Date: Sat, 19 Jun 2021 15:24:45 +0200
Subject: [PATCH 1/2] Merge formatting ranges that result in conflicting edits

---
 src/vs/editor/contrib/format/format.ts | 57 +++++++++++++++++++++-----
 1 file changed, 46 insertions(+), 11 deletions(-)

diff --git a/src/vs/editor/contrib/format/format.ts b/src/vs/editor/contrib/format/format.ts
index 7056eec2e5ada..7399898a18550 100644
--- a/src/vs/editor/contrib/format/format.ts
+++ b/src/vs/editor/contrib/format/format.ts
@@ -169,27 +169,62 @@ export async function formatDocumentRangesWithProvider(
 		}
 	}
 
-	const allEdits: TextEdit[] = [];
+	const computeEdits = async (range: Range) => {
+		const rawEdits = await provider.provideDocumentRangeFormattingEdits(
+			model,
+			range,
+			model.getFormattingOptions(),
+			cts.token
+		);
+		return (await workerService.computeMoreMinimalEdits(model.uri, rawEdits)) || [];
+	};
+
+	const hasIntersectingEdit = (a: TextEdit[], b: TextEdit[]) => {
+		for (let edit of a) {
+			for (let otherEdit of b) {
+				if (Range.intersectRanges(edit.range, otherEdit.range)) {
+					return true;
+				}
+			}
+		}
+		return false;
+	};
+
+	const rawEditsList: TextEdit[][] = [];
 	try {
 		for (let range of ranges) {
-			const rawEdits = await provider.provideDocumentRangeFormattingEdits(
-				model,
-				range,
-				model.getFormattingOptions(),
-				cts.token
-			);
-			const minEdits = await workerService.computeMoreMinimalEdits(model.uri, rawEdits);
-			if (minEdits) {
-				allEdits.push(...minEdits);
-			}
+			rawEditsList.push(await computeEdits(range));
 			if (cts.token.isCancellationRequested) {
 				return true;
 			}
 		}
+
+		for (let i = 0; i < ranges.length; ++i) {
+			for (let j = i + 1; j < ranges.length; ++j) {
+				if (cts.token.isCancellationRequested) {
+					return true;
+				}
+				if (hasIntersectingEdit(rawEditsList[i], rawEditsList[j])) {
+					// Merge ranges i and j into a single range, recompute the associated edits
+					const mergedRange = Range.plusRange(ranges[i], ranges[j]);
+					const edits = await computeEdits(mergedRange);
+					ranges.splice(j, 1);
+					ranges.splice(i, 1);
+					ranges.push(mergedRange);
+					rawEditsList.splice(j, 1);
+					rawEditsList.splice(i, 1);
+					rawEditsList.push(edits);
+					// Restart scanning
+					i = 0;
+					j = 0;
+				}
+			}
+		}
 	} finally {
 		cts.dispose();
 	}
 
+	const allEdits = rawEditsList.reduce((acc, val) => acc.concat(val), []);
 	if (allEdits.length === 0) {
 		return false;
 	}

From 974fce69e322054fa31830ee14d8d6904fcb6d6d Mon Sep 17 00:00:00 2001
From: Quentin Chateau <quentin.chateau@gmail.com>
Date: Mon, 21 Jun 2021 23:48:41 +0200
Subject: [PATCH 2/2] Optimize format range merging

---
 src/vs/editor/contrib/format/format.ts | 28 +++++++++++++++++++++-----
 1 file changed, 23 insertions(+), 5 deletions(-)

diff --git a/src/vs/editor/contrib/format/format.ts b/src/vs/editor/contrib/format/format.ts
index 7399898a18550..72f7aa9bdb6e7 100644
--- a/src/vs/editor/contrib/format/format.ts
+++ b/src/vs/editor/contrib/format/format.ts
@@ -170,16 +170,24 @@ export async function formatDocumentRangesWithProvider(
 	}
 
 	const computeEdits = async (range: Range) => {
-		const rawEdits = await provider.provideDocumentRangeFormattingEdits(
+		return (await provider.provideDocumentRangeFormattingEdits(
 			model,
 			range,
 			model.getFormattingOptions(),
 			cts.token
-		);
-		return (await workerService.computeMoreMinimalEdits(model.uri, rawEdits)) || [];
+		)) || [];
 	};
 
 	const hasIntersectingEdit = (a: TextEdit[], b: TextEdit[]) => {
+		if (!a.length || !b.length) {
+			return false;
+		}
+		// quick exit if the list of ranges are completely unrelated [O(n)]
+		const mergedA = a.reduce((acc, val) => { return Range.plusRange(acc, val.range); }, a[0].range);
+		if (!b.some(x => { return Range.intersectRanges(mergedA, x.range); })) {
+			return false;
+		}
+		// fallback to a complete check [O(n^2)]
 		for (let edit of a) {
 			for (let otherEdit of b) {
 				if (Range.intersectRanges(edit.range, otherEdit.range)) {
@@ -190,13 +198,14 @@ export async function formatDocumentRangesWithProvider(
 		return false;
 	};
 
+	const allEdits: TextEdit[] = [];
 	const rawEditsList: TextEdit[][] = [];
 	try {
 		for (let range of ranges) {
-			rawEditsList.push(await computeEdits(range));
 			if (cts.token.isCancellationRequested) {
 				return true;
 			}
+			rawEditsList.push(await computeEdits(range));
 		}
 
 		for (let i = 0; i < ranges.length; ++i) {
@@ -220,11 +229,20 @@ export async function formatDocumentRangesWithProvider(
 				}
 			}
 		}
+
+		for (let rawEdits of rawEditsList) {
+			if (cts.token.isCancellationRequested) {
+				return true;
+			}
+			const minimalEdits = await workerService.computeMoreMinimalEdits(model.uri, rawEdits);
+			if (minimalEdits) {
+				allEdits.push(...minimalEdits);
+			}
+		}
 	} finally {
 		cts.dispose();
 	}
 
-	const allEdits = rawEditsList.reduce((acc, val) => acc.concat(val), []);
 	if (allEdits.length === 0) {
 		return false;
 	}