Non-deterministic output for indented multiline strings

[kasperlewau]

Version

▸ yamlfmt --version
yamlfmt v0.21.0

Description

Running yamlfmt multiple times on the same file produces different output each time. The file keeps growing with additional blank lines.

Minimal Reproducible Example

config:
  sqlQuery: >-
    SELECT
      id,
      name
    FROM table

▸ xxd tmp.yaml
00000000: 636f 6e66 6967 3a0a 2020 7371 6c51 7565  config:.  sqlQue
00000010: 7279 3a20 3e2d 0a20 2020 2053 454c 4543  ry: >-.    SELEC
00000020: 540a 2020 2020 2020 6964 2c0a 2020 2020  T.      id,.
00000030: 2020 6e61 6d65 0a20 2020 2046 524f 4d20    name.    FROM
00000040: 7461 626c 650a                           table.

Run yamlfmt multiple times:

▸ md5sum tmp.yaml; yamlfmt tmp.yaml # e33add58f9e0e4b84aeb71a61c267d8e
▸ md5sum tmp.yaml; yamlfmt tmp.yaml # 7a3e92a06e68c33a5182d292fdae70ba
▸ md5sum tmp.yaml; yamlfmt tmp.yaml # ab174fb2a78b3c453e4bd7e104325e27

Expected Behavior

Output should be identical after the first run.

Actual Behavior

Each run produces a different checksum:

e33add58f9e0e4b84aeb71a61c267d8e  tmp.yaml  (original)
7a3e92a06e68c33a5182d292fdae70ba  tmp.yaml  (after run 1)
ab174fb2a78b3c453e4bd7e104325e27  tmp.yaml  (after run 2)
846858c950577d0ba4a0225038abb602  tmp.yaml  (after run 3)

After three consecutive yamlfmt tmp.yaml runs

▸ cat tmp.yaml
config:
  sqlQuery: >-
    SELECT



      id,
      name
    FROM table

▸ xxd tmp.yaml
00000000: 636f 6e66 6967 3a0a 2020 7371 6c51 7565  config:.  sqlQue
00000010: 7279 3a20 3e2d 0a20 2020 2053 454c 4543  ry: >-.    SELEC
00000020: 540a 0a0a 0a20 2020 2020 2069 642c 0a20  T....      id,.
00000030: 2020 2020 206e 616d 650a 2020 2020 4652       name.    FR
00000040: 4f4d 2074 6162 6c65 0a                   OM table.

The file grows, with blank lines being continuously added.

Workaround

De-indent lines 4 and 5 in the original tmp.yaml file. Consecutive runs of yamlfmt now produce stable output.

▸ cat tmp.yaml
config:
  sqlQuery: >-
    SELECT
    id,
    name
    FROM table

▸ md5sum tmp.yaml; xxd tmp.yaml; yamlfmt tmp.yaml
6c9e5f19314fb1b5dc7d7ec1a982e485  tmp.yaml
00000000: 636f 6e66 6967 3a0a 2020 7371 6c51 7565  config:.  sqlQue
00000010: 7279 3a20 3e2d 0a20 2020 2053 454c 4543  ry: >-.    SELEC
00000020: 5420 0a20 2020 2069 642c 200a 2020 2020  T .    id, .
00000030: 6e61 6d65 200a 2020 2020 4652 4f4d 2074  name .    FROM t
00000040: 6162 6c65 0a                             able.

▸ md5sum tmp.yaml; xxd tmp.yaml; yamlfmt tmp.yaml
eae04f655ee477d9ca6f156e16563ebb  tmp.yaml
00000000: 636f 6e66 6967 3a0a 2020 7371 6c51 7565  config:.  sqlQue
00000010: 7279 3a20 3e2d 0a20 2020 2053 454c 4543  ry: >-.    SELEC
00000020: 5420 2069 642c 2020 6e61 6d65 2020 4652  T  id,  name  FR
00000030: 4f4d 2074 6162 6c65 0a                   OM table.

▸ md5sum tmp.yaml; xxd tmp.yaml; yamlfmt tmp.yaml
eae04f655ee477d9ca6f156e16563ebb  tmp.yaml
00000000: 636f 6e66 6967 3a0a 2020 7371 6c51 7565  config:.  sqlQue
00000010: 7279 3a20 3e2d 0a20 2020 2053 454c 4543  ry: >-.    SELEC
00000020: 5420 2069 642c 2020 6e61 6d65 2020 4652  T  id,  name  FR
00000030: 4f4d 2074 6162 6c65 0a                   OM table.