printSourceLocation: simplifying by using padStart (#2981)

graphql · Mar 23, 2021 · a50dbd2 · a50dbd2
1 parent 9110135
commit a50dbd2
Showing 1 changed file with 10 additions and 21 deletions.
diff --git a/src/language/printLocation.js b/src/language/printLocation.js
@@ -21,7 +21,7 @@ export function printSourceLocation(
   sourceLocation: SourceLocation,
 ): string {
   const firstLineColumnOffset = source.locationOffset.column - 1;
-  const body = whitespace(firstLineColumnOffset) + source.body;
+  const body = ''.padStart(firstLineColumnOffset) + source.body;
 
   const lineIndex = sourceLocation.line - 1;
   const lineOffset = source.locationOffset.line - 1;
@@ -46,10 +46,10 @@ export function printSourceLocation(
     return (
       locationStr +
       printPrefixedLines([
-        [`${lineNum}`, subLines[0]],
-        ...subLines.slice(1, subLineIndex + 1).map((subLine) => ['', subLine]),
-        [' ', whitespace(subLineColumnNum - 1) + '^'],
-        ['', subLines[subLineIndex + 1]],
+        [`${lineNum} |`, subLines[0]],
+        ...subLines.slice(1, subLineIndex + 1).map((subLine) => ['|', subLine]),
+        ['|', '^'.padStart(subLineColumnNum)],
+        ['|', subLines[subLineIndex + 1]],
       ])
     );
   }
@@ -58,10 +58,10 @@ export function printSourceLocation(
     locationStr +
     printPrefixedLines([
       // Lines specified like this: ["prefix", "string"],
-      [`${lineNum - 1}`, lines[lineIndex - 1]],
-      [`${lineNum}`, locationLine],
-      ['', whitespace(columnNum - 1) + '^'],
-      [`${lineNum + 1}`, lines[lineIndex + 1]],
+      [`${lineNum - 1} |`, lines[lineIndex - 1]],
+      [`${lineNum} |`, locationLine],
+      ['|', '^'.padStart(columnNum)],
+      [`${lineNum + 1} |`, lines[lineIndex + 1]],
     ])
   );
 }
@@ -71,17 +71,6 @@ function printPrefixedLines(lines: $ReadOnlyArray<[string, string]>): string {
 
   const padLen = Math.max(...existingLines.map(([prefix]) => prefix.length));
   return existingLines
-    .map(
-      ([prefix, line]) =>
-        leftPad(padLen, prefix) + (line ? ' | ' + line : ' |'),
-    )
+    .map(([prefix, line]) => prefix.padStart(padLen) + (line ? ' ' + line : ''))
     .join('\n');
 }
-
-function whitespace(len: number): string {
-  return Array(len + 1).join(' ');
-}
-
-function leftPad(len: number, str: string): string {
-  return whitespace(len - str.length) + str;
-}