fix: Do not allow seq with single-line collection value on same line with map key (fixes #603)

Author: eemeli

src/parse/parser.ts

@@ -675,7 +675,21 @@ export class Parser {
         default: {
           const bv = this.startBlockValue(map)
           if (bv) {
-            if (atMapIndent && bv.type !== 'block-seq') {
+            if (bv.type === 'block-seq') {
+              if (
+                !it.explicitKey &&
+                it.sep &&
+                !includesToken(it.sep, 'newline')
+              ) {
+                yield* this.pop({
+                  type: 'error',
+                  offset: this.offset,
+                  message: 'Unexpected block-seq-ind on same line with key',
+                  source: this.source
+                })
+                return
+              }
+            } else if (atMapIndent) {
               map.items.push({ start })
             }
             this.stack.push(bv)

tests/doc/errors.ts

@@ -89,17 +89,15 @@ describe('block collections', () => {
   test('seq item in mapping', () => {
     const src = 'foo: "1"\n- bar\n'
     const doc = YAML.parseDocument(src)
-    expect(doc.errors).toMatchObject(
-      [
-        'A block sequence may not be used as an implicit map key',
-        'Implicit keys need to be on a single line',
-        'Implicit map keys need to be followed by map values'
-      ].map(msg => ({ message: expect.stringContaining(msg) }))
-    )
+    expect(doc.errors).toMatchObject([
+      { code: 'MULTILINE_IMPLICIT_KEY' },
+      { code: 'UNEXPECTED_TOKEN' },
+      { code: 'MISSING_CHAR' }
+    ])
     expect(doc.contents).toMatchObject({
       items: [
         { key: { value: 'foo' }, value: { value: '1' } },
-        { key: { items: [{ value: 'bar' }] }, value: null }
+        { key: { value: null }, value: null }
       ]
     })
   })
@@ -187,6 +185,11 @@ describe('block collections', () => {
     `)
     expect(doc.errors).toMatchObject([])
   })
+
+  test('sequence with compact mapping value on same line with mapping key (#603)', () => {
+    const doc = YAML.parseDocument('abc: - foo: bar')
+    expect(doc.errors).toMatchObject([{ code: 'UNEXPECTED_TOKEN' }])
+  })
 })
 
 describe('flow collections', () => {

tests/doc/foldFlowLines.ts

@@ -175,7 +175,7 @@ describe('double-quoted', () => {
         const res = YAML.parse(str)
         expect(res[0].key2).toBe(key2)
       })
-      
+
       test('minimal (#59)', () => {
         const str = `"######\\\\P#"`
         expect(fold(str, '', FOLD_QUOTED, options)).toBe(`"######\\\\\\\nP#"`)

tests/line-counter.ts

@@ -11,7 +11,7 @@ test('Parse error, no newlines', () => {
 test('Parse error with newlines', () => {
   const lineCounter = new LineCounter()
   const doc = parseDocument('foo:\n  bar: - baz\n', { lineCounter })
-  expect(doc.errors).toMatchObject([{ pos: [14, 17] }])
+  expect(doc.errors).toMatchObject([{ pos: [12, 13] }, { pos: [14, 17] }])
   expect(lineCounter.lineStarts).toMatchObject([0, 5, 18])
   expect(lineCounter.linePos(14)).toMatchObject({ line: 2, col: 10 })
   expect(lineCounter.linePos(17)).toMatchObject({ line: 2, col: 13 })