2861815f71
YAML scalars tagged `!!float` were round-tripped through `float64` and re-serialized by Go's JSON encoder, which strips the decimal part of whole-number floats. As a result, `50.0` came out as `50` and a sequence like `[50.0, 95.0, 99.0, 99.9]` became `[50,95,99,99.9]`, turning a uniform array of floats into a mixed int/float array that downstream consumers (Horreum, JSON Schema validators, jq, etc.) reject. The JSON spec does not distinguish ints from floats, but every common JSON library (Go's `encoding/json`, Python's `json`, jq) preserves the fractional form of values that came in as floats. yq's YAML decoder already parses these as `!!float` with the original text intact, so we can emit them verbatim instead of round-tripping. `MarshalJSON` for `ScalarNode` now special-cases `!!float`: - if `Value` is already a JSON-shaped number literal containing a `.` or exponent, emit it verbatim (e.g. `50.0`, `99.9`, `1.5e-3`, `-7.0`); - if `Value` is an integer-shaped string tagged `!!float` (e.g. `!!float 5`), format the parsed float and append `.0` so it stays a JSON number with a fractional part; - otherwise (empty value, parse error, or non-finite result), fall back to the existing encoding path so behaviour for `.inf` / `.nan` and anything unusual is unchanged. `!!int` nodes still encode as JSON integers. Closes #2683 Signed-off-by: ChrisJr404 <chris@hacknow.com>
4.6 KiB
JSON
Encode and decode to and from JSON. Supports multiple JSON documents in a single file (e.g. NDJSON).
Note that YAML is a superset of (single document) JSON - so you don't have to use the JSON parser to read JSON when there is only one JSON document in the input. You will probably want to pretty print the result in this case, to get idiomatic YAML styling.
Parse json: simple
JSON is a subset of yaml, so all you need to do is prettify the output
Given a sample.json file of:
{"cat": "meow"}
then
yq -p=json sample.json
will output
cat: meow
Parse json: complex
JSON is a subset of yaml, so all you need to do is prettify the output
Given a sample.json file of:
{"a":"Easy! as one two three","b":{"c":2,"d":[3,4]}}
then
yq -p=json sample.json
will output
a: Easy! as one two three
b:
c: 2
d:
- 3
- 4
Encode json: simple
Given a sample.yml file of:
cat: meow
then
yq -o=json '.' sample.yml
will output
{
"cat": "meow"
}
Encode json: simple - in one line
Given a sample.yml file of:
cat: meow # this is a comment, and it will be dropped.
then
yq -o=json -I=0 '.' sample.yml
will output
{"cat":"meow"}
Encode json: comments
Given a sample.yml file of:
cat: meow # this is a comment, and it will be dropped.
then
yq -o=json '.' sample.yml
will output
{
"cat": "meow"
}
Encode json: anchors
Anchors are dereferenced
Given a sample.yml file of:
cat: &ref meow
anotherCat: *ref
then
yq -o=json '.' sample.yml
will output
{
"cat": "meow",
"anotherCat": "meow"
}
Encode json: multiple results
Each matching node is converted into a json doc. This is best used with 0 indent (json document per line)
Given a sample.yml file of:
things: [{stuff: cool}, {whatever: cat}]
then
yq -o=json -I=0 '.things[]' sample.yml
will output
{"stuff":"cool"}
{"whatever":"cat"}
Encode json: preserve floats with trailing zero
Whole-number floats keep their decimal point so downstream consumers see a JSON number with a fractional part (matches Go's encoding/json, Python's json, and jq).
Given a sample.yml file of:
percentiles: [50.0, 95.0, 99.0, 99.9]
then
yq -o=json -I=0 '.' sample.yml
will output
{"percentiles":[50.0,95.0,99.0,99.9]}
Roundtrip JSON Lines / NDJSON
Given a sample.json file of:
{"this": "is a multidoc json file"}
{"each": ["line is a valid json document"]}
{"a number": 4}
then
yq -p=json -o=json -I=0 sample.json
will output
{"this":"is a multidoc json file"}
{"each":["line is a valid json document"]}
{"a number":4}
Roundtrip multi-document JSON
The parser can also handle multiple multi-line json documents in a single file (despite this not being in the JSON Lines / NDJSON spec). Typically you would have one entire JSON document per line, but the parser also supports multiple multi-line json documents
Given a sample.json file of:
{
"this": "is a multidoc json file"
}
{
"it": [
"has",
"consecutive",
"json documents"
]
}
{
"a number": 4
}
then
yq -p=json -o=json -I=2 sample.json
will output
{
"this": "is a multidoc json file"
}
{
"it": [
"has",
"consecutive",
"json documents"
]
}
{
"a number": 4
}
Update a specific document in a multi-document json
Documents are indexed by the documentIndex or di operator.
Given a sample.json file of:
{"this": "is a multidoc json file"}
{"each": ["line is a valid json document"]}
{"a number": 4}
then
yq -p=json -o=json -I=0 '(select(di == 1) | .each ) += "cool"' sample.json
will output
{"this":"is a multidoc json file"}
{"each":["line is a valid json document","cool"]}
{"a number":4}
Find and update a specific document in a multi-document json
Use expressions as you normally would.
Given a sample.json file of:
{"this": "is a multidoc json file"}
{"each": ["line is a valid json document"]}
{"a number": 4}
then
yq -p=json -o=json -I=0 '(select(has("each")) | .each ) += "cool"' sample.json
will output
{"this":"is a multidoc json file"}
{"each":["line is a valid json document","cool"]}
{"a number":4}
Decode JSON Lines / NDJSON
Given a sample.json file of:
{"this": "is a multidoc json file"}
{"each": ["line is a valid json document"]}
{"a number": 4}
then
yq -p=json sample.json
will output
this: is a multidoc json file
---
each:
- line is a valid json document
---
a number: 4