From 6df62788a1431646bdc427df0f316b508c4b88d2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ren=C3=A9=20Pfeuffer?= <rene.pfeuffer@cloudogu.com>
Date: Tue, 30 Jun 2020 11:00:36 +0200
Subject: [PATCH] Handle overlapping replacements

---
 .../changesets/textSplitAndReplace.test.ts    | 33 +++++++++++++++++++
 .../changesets/textSplitAndReplace.ts         | 13 +++++++-
 2 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/scm-ui/ui-webapp/src/repos/components/changesets/textSplitAndReplace.test.ts b/scm-ui/ui-webapp/src/repos/components/changesets/textSplitAndReplace.test.ts
index 641ff2cb9b..778236ee6d 100644
--- a/scm-ui/ui-webapp/src/repos/components/changesets/textSplitAndReplace.test.ts
+++ b/scm-ui/ui-webapp/src/repos/components/changesets/textSplitAndReplace.test.ts
@@ -98,4 +98,37 @@ describe("text split and replace", () => {
     expect(result[7]).toStrictEqual({ text: "We are going to die." });
     expect(result[8]).toStrictEqual({ text: "“" });
   });
+
+  it("should ignore conflicting replacements", () => {
+    const result = textSplitAndReplace<Wrapped>(
+      "'So this is it,' said Arthur, 'We are going to die.'",
+      [
+        { textToReplace: "said Arthur", replacement: { text: "to be replaced" } },
+        { textToReplace: " said", replacement: { text: "to be ignored 1" }, replaceAll: true },
+        { textToReplace: "d A", replacement: { text: "to be ignored 2" }, replaceAll: true },
+        { textToReplace: "Arthur,", replacement: { text: "to be ignored 3" }, replaceAll: true }
+      ],
+      testWrapper
+    );
+    expect(result).toHaveLength(3);
+    expect(result[0]).toStrictEqual({ text: "'So this is it,' " });
+    expect(result[1]).toStrictEqual({ text: "to be replaced" });
+    expect(result[2]).toStrictEqual({ text: ", 'We are going to die.'" });
+  });
+
+  it("should replace adjacent texts", () => {
+    const result = textSplitAndReplace<Wrapped>(
+      "'So this is it,' said Arthur, 'We are going to die.'",
+      [
+        { textToReplace: "'So this is it,'", replacement: { text: "one" } },
+        { textToReplace: " said Arthur, ", replacement: { text: "two" } },
+        { textToReplace: "'We are going to die.'", replacement: { text: "three" } }
+      ],
+      testWrapper
+    );
+    expect(result).toHaveLength(3);
+    expect(result[0]).toStrictEqual({ text: "one" });
+    expect(result[1]).toStrictEqual({ text: "two" });
+    expect(result[2]).toStrictEqual({ text: "three" });
+  });
 });
diff --git a/scm-ui/ui-webapp/src/repos/components/changesets/textSplitAndReplace.ts b/scm-ui/ui-webapp/src/repos/components/changesets/textSplitAndReplace.ts
index 1f4bcf3fad..c94f85f34c 100644
--- a/scm-ui/ui-webapp/src/repos/components/changesets/textSplitAndReplace.ts
+++ b/scm-ui/ui-webapp/src/repos/components/changesets/textSplitAndReplace.ts
@@ -34,6 +34,14 @@ type PartToReplace<T> = {
   replacement: T;
 };
 
+function hasConflict<T>(alreadyFoundReplacements: PartToReplace<T>[], newReplacement: PartToReplace<T>) {
+  return !!alreadyFoundReplacements.find(
+    existing =>
+      (existing.start <= newReplacement.start && existing.start + existing.length > newReplacement.start) ||
+      (newReplacement.start <= existing.start && newReplacement.start + newReplacement.length > existing.start)
+  );
+}
+
 export default function textSplitAndReplace<T>(
   text: string,
   replacements: Replacement<T>[],
@@ -47,7 +55,10 @@ export default function textSplitAndReplace<T>(
       const start = text.indexOf(replacement.textToReplace, lastIndex);
       if (start >= 0) {
         const length = replacement.textToReplace.length;
-        partsToReplace.push({ start, length, replacement: replacement.replacement });
+        const newReplacement = { start, length, replacement: replacement.replacement };
+        if (!hasConflict(partsToReplace, newReplacement)) {
+          partsToReplace.push(newReplacement);
+        }
         lastIndex = start + length;
       } else {
         lastIndex = -1;