Fix tests and some bugs

MetaMask · Sep 14, 2021 · 892a0a1 · 892a0a1
1 parent 662f5ae
commit 892a0a1
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Showing 2 changed files with 63 additions and 28 deletions.
diff --git a/development/build/transforms/remove-fenced-code.js b/development/build/transforms/remove-fenced-code.js
@@ -120,10 +120,13 @@ const CommandValidators = {
   },
 };
 
-// Matches lines starting with "///:", optionally preceded by whitespace
-const linesWithFenceRegex = /^\s*\/\/\/:.*$/gmu;
+// Matches lines starting with "///:", and any preceding whitespace, except
+// newlines. We except newlines to avoid eating blank lines preceding a fenced
+// line.
+// Double-negative RegEx credit: https://stackoverflow.com/a/3469155
+const linesWithFenceRegex = /^[^\S\r\n]*\/\/\/:.*$/gmu;
 
-// Matches the first "///:" in a string
+// Matches the first "///:" in a string, and any preceding whitespace
 const fenceSentinelRegex = /^\s*\/\/\/:/u;
 
 // Breaks a fence directive into its constituent components
@@ -170,6 +173,7 @@ function removeFencedCode(filePath, typeOfCurrentBuild, fileContent) {
   const parsedDirectives = matchedLines.map((matchArray) => {
     const line = matchArray[0];
 
+    /* istanbul ignore next: should be impossible */
     if (!fenceSentinelRegex.test(line)) {
       throw new Error(
         getInvalidFenceLineMessage(
@@ -185,8 +189,8 @@ function removeFencedCode(filePath, typeOfCurrentBuild, fileContent) {
     // performing string operations.
     const indices = [matchArray.index, matchArray.index + line.length + 1];
 
-    const unfencedLine = line.replace(fenceSentinelRegex, '');
-    if (!/^ \w\w+/u.test(unfencedLine)) {
+    const lineWithoutSentinel = line.replace(fenceSentinelRegex, '');
+    if (!/^ \w\w+/u.test(lineWithoutSentinel)) {
       throw new Error(
         getInvalidFenceLineMessage(
           filePath,
@@ -196,7 +200,10 @@ function removeFencedCode(filePath, typeOfCurrentBuild, fileContent) {
       );
     }
 
-    const directiveMatches = unfencedLine.trim().match(directiveParsingRegex);
+    const directiveMatches = lineWithoutSentinel
+      .trim()
+      .match(directiveParsingRegex);
+
     if (!directiveMatches) {
       throw new Error(
         getInvalidFenceLineMessage(
@@ -371,10 +378,12 @@ function multiSplice(toSplice, splicingIndices) {
   // It iterates over all "end" indices of the array except the last one, and
   // pushes the substring between each "end" index and the next "begin" index
   // to the array of retained substrings.
-  for (let i = 1; i < splicingIndices.length; i += 2) {
-    retainedSubstrings.push(
-      toSplice.substring(splicingIndices[i], splicingIndices[i + 1]),
-    );
+  if (splicingIndices.length > 2) {
+    for (let i = 1; i < splicingIndices.length; i += 2) {
+      retainedSubstrings.push(
+        toSplice.substring(splicingIndices[i], splicingIndices[i + 1]),
+      );
+    }
   }
 
   // Get the last part to be included

diff --git a/development/build/transforms/remove-fenced-code.test.js b/development/build/transforms/remove-fenced-code.test.js
@@ -147,6 +147,50 @@ describe('build/transforms/remove-fenced-code', () => {
       });
     });
 
+    // This is an edge case for the splicing function
+    it('transforms file with two fence lines', () => {
+      expect(
+        removeFencedCode(
+          mockFileName,
+          BuildTypes.flask,
+          getMinimalFencedCode('main'),
+        ),
+      ).toStrictEqual(['', true]);
+    });
+
+    it('ignores sentinels preceded by non-whitespace', () => {
+      const validBeginDirective = '///: BEGIN:ONLY_INCLUDE_IN(flask)\n';
+      const ignoredLines = [
+        `a ${validBeginDirective}`,
+        `2 ${validBeginDirective}`,
+        `@ ${validBeginDirective}`,
+      ];
+
+      ignoredLines.forEach((ignoredLine) => {
+        // These inputs will be transformed
+        expect(
+          removeFencedCode(
+            mockFileName,
+            BuildTypes.flask,
+            getMinimalFencedCode('main').concat(ignoredLine),
+          ),
+        ).toStrictEqual([ignoredLine, true]);
+
+        const modifiedInputWithoutFences = testData.validInputs.withoutFences.concat(
+          ignoredLine,
+        );
+
+        // These inputs will not be transformed
+        expect(
+          removeFencedCode(
+            mockFileName,
+            BuildTypes.flask,
+            modifiedInputWithoutFences,
+          ),
+        ).toStrictEqual([modifiedInputWithoutFences, false]);
+      });
+    });
+
     // Invalid inputs
     it('rejects empty fences', () => {
       const jsComment = '// A comment\n';
@@ -177,24 +221,6 @@ describe('build/transforms/remove-fenced-code', () => {
       });
     });
 
-    it('rejects sentinels preceded by non-whitespace', () => {
-      // Matches the sentinel component of the first line beginning with "///:"
-      const fenceSentinelRegex = /^\/\/\/:/mu;
-      const replacements = ['a ///:', '2 ///:', '_ ///:'];
-
-      replacements.forEach((replacement) => {
-        expect(() =>
-          removeFencedCode(
-            mockFileName,
-            BuildTypes.flask,
-            getMinimalFencedCode().replace(fenceSentinelRegex, replacement),
-          ),
-        ).toThrow(
-          /Fence sentinel may only appear at the start of a line, optionally preceded by whitespace.$/u,
-        );
-      });
-    });
-
     it('rejects sentinels not followed by a single space and a multi-character alphabetical string', () => {
       // Matches the sentinel and terminus component of the first line
       // beginning with "///: TERMINUS"