Fix L24T-2.yaml (value of blockLiteral) bug in yaml-test-suite (#18331)

Co-authored-by: fisker <lionkay@gmail.com>

changelog_unreleased/yaml/18331.md

@@ -0,0 +1,16 @@
+#### Fix block value ends with whitespace (#18331 by @kovsu)
+
+```js
+import { inspect } from "node:util";
+import * as prettier from "prettier";
+
+const input = "foo: |\n  x\n   ";
+const output = await prettier.format(input, { parser: "yaml" });
+console.log(inspect(output));
+
+// Prettier stable
+//-> 'foo: |\n  x\n\n'
+
+// Prettier main
+//-> 'foo: |\n  x\n'
+```

src/language-yaml/clean.js

@@ -21,6 +21,18 @@ function clean(original, cloned /* , parent */) {
         delete cloned.documentEndMarker;
       }
       break;
+
+    case "blockLiteral":
+    case "blockFolded":
+      // The doc printer currently have bug when print trailing space/tab, they get wiped.
+      // But at least we can still make sure the new lines doesn't change in `value` property.
+      if (original.chomping === "keep") {
+        cloned.value = original.value
+          .split("\n")
+          .map((line) => line.replace(/[ \t]+$/u, ""))
+          .join("\n");
+      }
+      break;
   }
 }
 clean.ignoredProperties = new Set(["position"]);

src/language-yaml/utilities.js

@@ -209,6 +209,10 @@ function getBlockValueLineContents(
           // exclude open line `>` or `|`
           .match(/^[^\n]*\n(.*)$/su)[1];
 
+  if (content === "") {
+    return [];
+  }
+
   /** @type {number} */
   let leadingSpaceCount;
   if (node.indent === null) {
@@ -275,14 +279,16 @@ function getBlockValueLineContents(
   */
   function removeUnnecessaryTrailingNewlines(lineContents) {
     if (node.chomping === "keep") {
-      return lineContents.at(-1).length === 0
+      return content.endsWith("\n") && lineContents.at(-1).length === 0
         ? lineContents.slice(0, -1)
         : lineContents;
     }
 
     let trailingNewlineCount = 0;
     for (let i = lineContents.length - 1; i >= 0; i--) {
-      if (lineContents[i].length === 0) {
+      if (
+        lineContents[i].every((line) => line.replace(/[ \t]+$/u, "") === "")
+      ) {
         trailingNewlineCount++;
       } else {
         break;

tests/format/yaml/block-value/format.test.js

@@ -0,0 +1,27 @@
+const blockStyles = ["|", ">", "|+", "|-", ">+", ">-"];
+const trailingSpace = ["", "  ", "\t"];
+const newlines = ["", "\n", "\n\n", "\n\n\n"];
+
+const snippets = blockStyles.flatMap((blockStyle) =>
+  trailingSpace.flatMap((space) =>
+    newlines.flatMap((lines) =>
+      [
+        `foo: ${blockStyle}\n${lines}`,
+        // `foo: ${blockStyle}\n  ${space}${lines}`,
+        `foo: ${blockStyle}\n  x\n${lines}`,
+        `foo: ${blockStyle}\n  x\n${space}\n${lines}`,
+      ].flatMap((code) => [code, `${code}\n...`]),
+    ),
+  ),
+);
+
+runFormatTest(
+  {
+    importMeta: import.meta,
+    snippets: snippets.map((code) => ({
+      name: JSON.stringify(code),
+      code,
+    })),
+  },
+  ["yaml"],
+);

tests/format/yaml/yaml-test-suite/__snapshots__/format.test.js.snap

@@ -4120,6 +4120,22 @@ foo: |
 ================================================================================
 `;
 
+exports[`snippet: L24T-2.yaml - Trailing line of spaces format 1`] = `
+====================================options=====================================
+parsers: ["yaml"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+foo: |
+  x
+   
+=====================================output=====================================
+foo: |
+  x
+
+================================================================================
+`;
+
 exports[`snippet: L94M.yaml - Tags in Explicit Mapping format 1`] = `
 ====================================options=====================================
 parsers: ["yaml"]

tests/format/yaml/yaml-test-suite/format.test.js

@@ -15,7 +15,6 @@ const BUGS = new Set([
   "DE56-4.yaml",
   "JEF9-2.yaml",
   "JEF9-3.yaml",
-  "L24T-2.yaml",
 ]);
 
 runFormatTest(