Wrapper rule around the popular `jq` utility. For jq documentation, see https://stedolan.github.io/jq/. ## Usage examples ```starlark load("@aspect_bazel_lib//lib:jq.bzl", "jq") ``` Create a new file `bazel-out/.../no_srcs.json` containing some JSON data: ```starlark jq( name = "no_srcs", srcs = [], filter = ".name = "Alice"", ) ``` Remove a field from `package.json`: > The output path `bazel-out/.../package.json` matches the path of the source file, > which means you must refer to the label `:no_dev_deps` to reference the output, > since Bazel doesn't provide a label for an output file that collides with an input file. ```starlark jq( name = "no_dev_deps", srcs = ["package.json"], filter = "del(.devDependencies)", ) ``` Merge data from `bar.json` on top of `foo.json`, producing `foobar.json`: ```starlark jq( name = "merged", srcs = ["foo.json", "bar.json"], filter = ".[0] * .[1]", args = ["--slurp"], out = "foobar.json", ) ``` Long filters can be split over several lines with comments: ```starlark jq( name = "complex", srcs = ["a.json", "b.json"], filter = """ .[0] as $a # Take select fields from b.json | (.[1] | {foo, bar, tags}) as $b # Merge b onto a | ($a * $b) # Combine 'tags' array from both | .tags = ($a.tags + $b.tags) # Add new field + {\"aspect_is_cool\": true} """, args = ["--slurp"], ) ``` Load filter from a file `filter.jq`, making it easier to edit complex filters: ```starlark jq( name = "merged", srcs = ["foo.json", "bar.json"], filter_file = "filter.jq", args = ["--slurp"], out = "foobar.json", ) ``` Convert [genquery](https://bazel.build/reference/be/general#genquery) output to JSON. ```starlark genquery( name = "deps", expression = "deps(//some:target)", scope = ["//some:target"], ) jq( name = "deps_json", srcs = [":deps"], args = [ "--raw-input", "--slurp", ], filter = "{ deps: split("\n") | map(select(. | length > 0)) }", ) ``` When Bazel is run with `--stamp`, replace some properties with version control info: ```starlark jq( name = "stamped", srcs = ["package.json"], filter = "|".join([ # Don't directly reference $STAMP as it's only set when stamping # This 'as' syntax results in $stamp being null in unstamped builds. "$ARGS.named.STAMP as $stamp", # Provide a default using the "alternative operator" in case $stamp is null. ".version = ($stamp[0].BUILD_EMBED_LABEL // "")", ]), ) ``` jq is exposed as a "Make variable", so you could use it directly from a `genrule` by referencing the toolchain. ```starlark genrule( name = "case_genrule", srcs = ["a.json"], outs = ["genrule_output.json"], cmd = "$(JQ_BIN) '.' $(location a.json) > $@", toolchains = ["@jq_toolchains//:resolved_toolchain"], ) ``` ## jq

jq(name, srcs, filter, filter_file, args, out, data, expand_args, kwargs)

Invoke jq with a filter on a set of json input files. **PARAMETERS** | Name | Description | Default Value | | :------------- | :------------- | :------------- | | name | Name of the rule | none | | srcs | List of input files. May be empty. | none | | filter | Filter expression (https://stedolan.github.io/jq/manual/#Basicfilters). Subject to stamp variable replacements, see [Stamping](./stamping.md). When stamping is enabled, a variable named "STAMP" will be available in the filter.

Be careful to write the filter so that it handles unstamped builds, as in the example above. | `None` | | filter_file | File containing filter expression (alternative to `filter`) | `None` | | args | Additional args to pass to jq | `[]` | | out | Name of the output json file; defaults to the rule name plus ".json" | `None` | | data | List of additional files. May be empty. | `[]` | | expand_args | Run bazel's location-expansion on the args. | `False` | | kwargs | Other common named parameters such as `tags` or `visibility` | none |