Changeset: Invert conditions to improve readability

src/static/js/Changeset.js

@@ -425,7 +425,7 @@ exports.mergingOpAssembler = () => {
   let bufOpAdditionalCharsAfterNewline = 0;
 
   const flush = (isEndDocument) => {
-    if (bufOp.opcode) {
+    if (!bufOp.opcode) return;
     if (isEndDocument && bufOp.opcode === '=' && !bufOp.attribs) {
       // final merged keep, leave it implicit
     } else {
@@ -438,11 +438,10 @@ exports.mergingOpAssembler = () => {
       }
     }
     bufOp.opcode = '';
-    }
   };
 
   const append = (op) => {
-    if (op.chars > 0) {
+    if (op.chars <= 0) return;
     if (bufOp.opcode === op.opcode && bufOp.attribs === op.attribs) {
       if (op.lines > 0) {
         // bufOp and additional chars are all mergeable into a multi-line op
@@ -460,7 +459,6 @@ exports.mergingOpAssembler = () => {
       flush();
       copyOp(op, bufOp);
     }
-    }
   };
 
   const endDocument = () => {
@@ -762,11 +760,9 @@ const textLinesMutator = (lines) => {
    * @param {boolean} includeInSplice - indicates if attributes are present
    */
   const skipLines = (L, includeInSplice) => {
-    if (L) {
+    if (!L) return;
     if (includeInSplice) {
-        if (!inSplice) {
+      if (!inSplice) enterSplice();
-          enterSplice();
-        }
       // TODO(doc) should this count the number of characters that are skipped to check?
       for (let i = 0; i < L; i++) {
         curCol = 0;
@@ -786,7 +782,6 @@ const textLinesMutator = (lines) => {
       curCol = 0;
     }
     // tests case foo in remove(), which isn't otherwise covered in current impl
-    }
   };
 
   /**
@@ -797,13 +792,11 @@ const textLinesMutator = (lines) => {
    * @param {boolean} includeInSplice - indicates if attributes are present
    */
   const skip = (N, L, includeInSplice) => {
-    if (N) {
+    if (!N) return;
     if (L) {
       skipLines(L, includeInSplice);
     } else {
-        if (includeInSplice && !inSplice) {
+      if (includeInSplice && !inSplice) enterSplice();
-          enterSplice();
-        }
       if (inSplice) {
         // although the line is put into splice curLine is not increased, because
         // only some chars are skipped, not the whole line
@@ -811,7 +804,6 @@ const textLinesMutator = (lines) => {
       }
       curCol += N;
     }
-    }
   };
 
   /**
@@ -821,11 +813,8 @@ const textLinesMutator = (lines) => {
    * @returns {string}
    */
   const removeLines = (L) => {
-    let removed = '';
+    if (!L) return '';
-    if (L) {
+    if (!inSplice) enterSplice();
-      if (!inSplice) {
-        enterSplice();
-      }
 
     /**
      * Gets a string of joined lines after the end of the splice.
@@ -837,6 +826,8 @@ const textLinesMutator = (lines) => {
       const m = curSplice[0] + curSplice[1];
       return linesSlice(m, m + k).join('');
     };
+
+    let removed = '';
     if (isCurLineInSplice()) {
       if (curCol === 0) {
         removed = curSplice[curSplice.length - 1];
@@ -856,7 +847,6 @@ const textLinesMutator = (lines) => {
       removed = nextKLinesText(L);
       curSplice[1] += L;
     }
-    }
     return removed;
   };
 
@@ -868,22 +858,15 @@ const textLinesMutator = (lines) => {
    * @returns {string}
    */
   const remove = (N, L) => {
-    let removed = '';
+    if (!N) return '';
-    if (N) {
+    if (L) return removeLines(L);
-      if (L) {
+    if (!inSplice) enterSplice();
-        return removeLines(L);
-      } else {
-        if (!inSplice) {
-          enterSplice();
-        }
     // although the line is put into splice, curLine is not increased, because
     // only some chars are removed not the whole line
     const sline = putCurLineInSplice();
-        removed = curSplice[sline].substring(curCol, curCol + N);
+    const removed = curSplice[sline].substring(curCol, curCol + N);
     curSplice[sline] = curSplice[sline].substring(0, curCol) +
         curSplice[sline].substring(curCol + N);
-      }
-    }
     return removed;
   };
 
@@ -894,10 +877,8 @@ const textLinesMutator = (lines) => {
    * @param {number} L - number of newlines in text
    */
   const insert = (text, L) => {
-    if (text) {
+    if (!text) return;
-      if (!inSplice) {
+    if (!inSplice) enterSplice();
-        enterSplice();
-      }
     if (L) {
       const newLines = exports.splitTextLines(text);
       if (isCurLineInSplice()) {
@@ -932,7 +913,6 @@ const textLinesMutator = (lines) => {
           curSplice[sline].substring(curCol);
       curCol += text.length;
     }
-    }
   };
 
   /**
@@ -1171,7 +1151,7 @@ exports.composeAttributes = (att1, att2, resultIsMutation, pool) => {
     let found = false;
     for (let i = 0; i < atts.length; i++) {
       const oldPair = atts[i];
-      if (oldPair[0] === pair[0]) {
+      if (oldPair[0] !== pair[0]) continue;
       if (pair[1] || resultIsMutation) {
         oldPair[1] = pair[1];
       } else {
@@ -1180,7 +1160,6 @@ exports.composeAttributes = (att1, att2, resultIsMutation, pool) => {
       found = true;
       break;
     }
-    }
     if ((!found) && (pair[1] || resultIsMutation)) {
       atts.push(pair);
     }
@@ -1340,12 +1319,11 @@ exports.mutateAttributionLines = (cs, lines, pool) => {
       lineAssem = exports.mergingOpAssembler();
     }
     lineAssem.append(op);
-    if (op.lines > 0) {
+    if (op.lines <= 0) return;
     assert(op.lines === 1, `Can't have op.lines of ${op.lines} in attribution lines`);
     // ship it to the mut
     mut.insert(lineAssem.toString(), 1);
     lineAssem = null;
-    }
   };
 
   const csOp = exports.newOp();
@@ -1505,16 +1483,11 @@ exports.compose = (cs1, cs2, pool) => {
  */
 exports.attributeTester = (attribPair, pool) => {
   const never = (attribs) => false;
-  if (!pool) {
+  if (!pool) return never;
-    return never;
-  }
   const attribNum = pool.putAttrib(attribPair, true);
-  if (attribNum < 0) {
+  if (attribNum < 0) return never;
-    return never;
-  } else {
   const re = new RegExp(`\\*${exports.numToString(attribNum)}(?!\\w)`);
   return (attribs) => re.test(attribs);
-  }
 };
 
 /**
@@ -1796,14 +1769,11 @@ exports.applyToAText = (cs, atext, pool) => ({
  * @returns {AText}
  */
 exports.cloneAText = (atext) => {
-  if (atext) {
+  if (!atext) error('atext is null');
   return {
     text: atext.text,
     attribs: atext.attribs,
   };
-  } else {
-    error('atext is null');
-  }
 };
 
 /**
@@ -1902,14 +1872,13 @@ exports.opAttributeValue = (op, key, pool) => exports.attribsAttributeValue(op.a
  * @returns {string}
  */
 exports.attribsAttributeValue = (attribs, key, pool) => {
+  if (!attribs) return '';
   let value = '';
-  if (attribs) {
   exports.eachAttribNumber(attribs, (n) => {
     if (pool.getAttribKey(n) === key) {
       value = pool.getAttribValue(n);
     }
   });
-  }
   return value;
 };
 
@@ -2038,7 +2007,7 @@ exports.subattribution = (astr, start, optEnd) => {
   const opOut = exports.newOp();
 
   const doCsOp = () => {
-    if (csOp.chars) {
+    if (!csOp.chars) return;
     while (csOp.opcode && (attOp.opcode || iter.hasNext())) {
       if (!attOp.opcode) iter.next(attOp);
 
@@ -2053,7 +2022,6 @@ exports.subattribution = (astr, start, optEnd) => {
         opOut.opcode = '';
       }
     }
-    }
   };
 
   csOp.opcode = '-';
@@ -2399,14 +2367,13 @@ const followAttributes = (att1, att2, pool) => {
     const pair1 = pool.getAttrib(exports.parseNum(a));
     for (let i = 0; i < atts.length; i++) {
       const pair2 = atts[i];
-      if (pair1[0] === pair2[0]) {
+      if (pair1[0] !== pair2[0]) continue;
       if (pair1[1] <= pair2[1]) {
         // winner of merge is pair1, delete this attribute
         atts.splice(i, 1);
       }
       break;
     }
-    }
     return '';
   });
   // we've only removed attributes, so they're already sorted