Handle escaped backslashes

src/matching/quoteMatcher.ts

@@ -5,29 +5,28 @@ export class QuoteMatcher {
   static escapeChar = "\\";
 
   static findOpening(char: string, corpus: string, start: number): number {
-    // first, search backwards to see if we could be inside a quote
+    // First, search backwards to see if we could be inside a quote
     for (let i = start - 1; i >= 0; i--) {
       const currentChar = corpus[i];
-      if (currentChar === char && corpus[i - 1] !== this.escapeChar) {
+      if (currentChar === char &&
+          (corpus[i - 1] !== this.escapeChar ||
+           corpus[i - 2] === this.escapeChar)) {
         return i;
       }
     }
 
-    // Didn't find one behind us, the string may start ahead of us
-    for (let i = start; i < corpus.length; i++) {
-      const currentChar = corpus[i];
-      if (currentChar === char && corpus[i - 1] !== this.escapeChar) {
-        return i;
-      }
-    }
-    return -1;
+    // Didn't find one behind us, the string may start ahead of us. This happens
+    // to be the same logic we use to search forwards.
+    return this.findClosing(char, corpus, start);
   }
 
   static findClosing(char: string, corpus: string, start: number): number {
     // Search forwards from start, looking for a non-escaped char
     for (let i = start; i < corpus.length; i++) {
       const currentChar = corpus[i];
-      if (currentChar === char && corpus[i - 1] !== this.escapeChar) {
+      if (currentChar === char &&
+          (corpus[i - 1] !== this.escapeChar ||
+           corpus[i - 2] === this.escapeChar)) {
         return i;
       }
     }

test/mode/modeNormal.test.ts

@@ -403,6 +403,22 @@ suite("Mode Normal", () => {
       endMode: ModeName.Insert
     });
 
+    newTest({
+      title: "Can handle 'ci\"' with an escaped backslash",
+      start: ['one "tw|o \\\\three"'],
+      keysPressed: 'ci"',
+      end: ['one "|"'],
+      endMode: ModeName.Insert
+    });
+
+    newTest({
+      title: "Can handle 'ci\"' with an escaped backslash on closing quote",
+      start: ['"\\\\|"'],
+      keysPressed: 'ci"',
+      end: ['"|"'],
+      endMode: ModeName.Insert
+    });
+
     newTest({
       title: "Can handle 'ca\"' starting on the closing quote",
       start: ['one "two|"'],