fix(json-ot): 🐛 fix another compose() bug

Author: streamich

src/json-ot/types/ot-string/StringType.ts

@@ -197,32 +197,26 @@ export const compose = (op1: StringTypeOp, op2: StringTypeOp): StringTypeOp => {
         const comp1 = i1 >= len1 ? remaining : op1[i1];
         const length1 = componentLength(comp1);
         const isDelete = idDeleteComponent(comp1);
-        if (remaining >= (length1 - off1)) {
-          if (isDelete) {
-            append(op3, copyComponent(comp1));
-            i1++;
-            off1 = 0;
-          } else {
-            const end = off2 + (length1 - off1);
-            switch (typeof comp1) {
-              case 'number': append(op3, isReversible ? [comp2[0].substring(off2, end)] : -length1); break;
-              case 'string': {
-                off2 += (length1 - off1);
-                break;
-              }
+        if (isDelete) {
+          append(op3, copyComponent(comp1));
+          i1++;
+          off1 = 0;
+        } else if (remaining >= (length1 - off1)) {
+          const end = off2 + (length1 - off1);
+          switch (typeof comp1) {
+            case 'number': append(op3, isReversible ? [comp2[0].substring(off2, end)] : -length1); break;
+            case 'string': {
+              off2 += (length1 - off1);
+              break;
             }
-            i1++;
-            off1 = 0;
-            off2 = end;
           }
+          i1++;
+          off1 = 0;
+          off2 = end;
         } else {
-          if (isDelete) {
-            append(op3, copyComponent(comp1));
-          } else {
-            switch (typeof comp1) {
-              case 'number': append(op3, isReversible ? [comp2[0].substring(off2)] : -remaining); break;
-              // case 'string': break;
-            }
+          switch (typeof comp1) {
+            case 'number': append(op3, isReversible ? [comp2[0].substring(off2)] : -remaining); break;
+            // case 'string': break;
           }
           off1 += remaining;
           off2 = length2;

src/json-ot/types/ot-string/__tests__/StringType.spec.ts

@@ -105,6 +105,7 @@ describe('compose()', () => {
     ['fuzzer bug #1', 'd6', ['}B'], [['}'], ';0q', 2, ['6']], ';0qBd'],
     ['fuzzer bug #2', 'Ai', [['A'], '#', -1], [-1], ''],
     ['fuzzer bug #3', 'M}', ['!y1'], ["'/*s", 2, ',/@', -2, ['}']], "'/*s!y,/@"],
+    ['fuzzer bug #4', '8sL', [-2, 'w', ['L']], [['w']], ''],
   ];
 
   describe('can compose', () => {

src/json-ot/types/ot-string/__tests__/fuzzer.compose.spec.ts

@@ -4,11 +4,11 @@ import {StringOtFuzzer} from './StringOtFuzzer';
 const fuzzer = new StringOtFuzzer();
 
 test('works', () => {
-  for (let i = 0; i < 100; i++) {
+  for (let i = 0; i < 100000; i++) {
     const str1 = fuzzer.genString();
-    let op1 = fuzzer.genOp(str1);
+    const op1 = fuzzer.genOp(str1);
     const str2 = apply(str1, op1);
-    let op2 = fuzzer.genOp(str2);
+    const op2 = fuzzer.genOp(str2);
     const str3 = apply(str2, op2);
     const op3 = compose(op1, op2);
     const str4 = apply(str1, op3);