fix: First-line folding for block scalars (fixes #422)

Author: eemeli

src/stringify/stringifyString.ts

@@ -15,8 +15,11 @@ interface StringifyScalar {
   type?: string
 }
 
-const getFoldOptions = (ctx: StringifyContext): FoldOptions => ({
-  indentAtStart: ctx.indentAtStart,
+const getFoldOptions = (
+  ctx: StringifyContext,
+  isBlock: boolean
+): FoldOptions => ({
+  indentAtStart: isBlock ? ctx.indent.length : ctx.indentAtStart,
   lineWidth: ctx.options.lineWidth,
   minContentWidth: ctx.options.minContentWidth
 })
@@ -132,7 +135,7 @@ function doubleQuotedString(value: string, ctx: StringifyContext) {
   str = start ? str + json.slice(start) : json
   return implicitKey
     ? str
-    : foldFlowLines(str, indent, FOLD_QUOTED, getFoldOptions(ctx))
+    : foldFlowLines(str, indent, FOLD_QUOTED, getFoldOptions(ctx, false))
 }
 
 function singleQuotedString(value: string, ctx: StringifyContext) {
@@ -148,7 +151,7 @@ function singleQuotedString(value: string, ctx: StringifyContext) {
     "'" + value.replace(/'/g, "''").replace(/\n+/g, `$&\n${indent}`) + "'"
   return ctx.implicitKey
     ? res
-    : foldFlowLines(res, indent, FOLD_FLOW, getFoldOptions(ctx))
+    : foldFlowLines(res, indent, FOLD_FLOW, getFoldOptions(ctx, false))
 }
 
 function quotedString(value: string, ctx: StringifyContext) {
@@ -254,7 +257,7 @@ function blockString(
     `${start}${value}${end}`,
     indent,
     FOLD_BLOCK,
-    getFoldOptions(ctx)
+    getFoldOptions(ctx, true)
   )
   return `${header}\n${indent}${body}`
 }
@@ -318,7 +321,7 @@ function plainString(
   }
   return implicitKey
     ? str
-    : foldFlowLines(str, indent, FOLD_FLOW, getFoldOptions(ctx))
+    : foldFlowLines(str, indent, FOLD_FLOW, getFoldOptions(ctx, false))
 }
 
 export function stringifyString(

tests/doc/foldFlowLines.js

@@ -1,5 +1,6 @@
 import * as YAML from 'yaml'
 import { foldFlowLines as fold } from 'yaml/util'
+import { source } from '../_utils'
 
 const FOLD_FLOW = 'flow'
 const FOLD_QUOTED = 'quoted'
@@ -250,6 +251,31 @@ describe('double-quoted', () => {
   })
 })
 
+describe('block scalar', () => {
+  test('eemeli/yaml#422', () => {
+    const obj = {
+      'nginx.ingress.kubernetes.io/configuration-snippet': source`
+          location ~* ^/sites/aaaaaaa.aa/files/(.+) {
+            return 302 https://process.aaaaaaa.aa/sites/aaaaaaa.aa/files/$1;
+          }
+          location ~* ^/partner-application/cls/(.+) {
+            return 301 https://process.aaaaaaa.aa/partner-application/cls/$1$is_args$args;
+          }
+          `
+    }
+    expect(YAML.stringify(obj)).toBe(source`
+        nginx.ingress.kubernetes.io/configuration-snippet: >
+          location ~* ^/sites/aaaaaaa.aa/files/(.+) {
+            return 302 https://process.aaaaaaa.aa/sites/aaaaaaa.aa/files/$1;
+          }
+
+          location ~* ^/partner-application/cls/(.+) {
+            return 301 https://process.aaaaaaa.aa/partner-application/cls/$1$is_args$args;
+          }
+      `)
+  })
+})
+
 describe('end-to-end', () => {
   const foldOptions = { lineWidth: 20, minContentWidth: 0 }