"""Public API for jq""" load("//lib/private:jq.bzl", _jq_lib = "jq_lib") _jq_rule = rule( attrs = _jq_lib.attrs, implementation = _jq_lib.implementation, toolchains = ["@aspect_bazel_lib//lib:jq_toolchain_type"], ) def jq(name, srcs, filter = None, filter_file = None, args = [], out = None, **kwargs): """Invoke jq with a filter on a set of json input files. For jq documentation, see https://stedolan.github.io/jq/. To use this rule you must register the jq toolchain in your WORKSPACE: ```starlark load("@aspect_bazel_lib//lib:repositories.bzl", "register_jq_toolchains") register_jq_toolchains() ``` Usage examples: ```starlark load("@aspect_bazel_lib//lib:jq.bzl", "jq") # Create a new file bazel-out/.../no_srcs.json jq( name = "no_srcs", srcs = [], filter = ".name = \"Alice\"", ) # Remove fields from package.json. # Writes to bazel-out/.../package.json which means you must refer to this as ":no_dev_deps" # since Bazel doesn't allow a label for the output file that collides with the input file. jq( name = "no_dev_deps", srcs = ["package.json"], filter = "del(.devDependencies)", ) # Merge bar.json on top of foo.json, producing foobar.json 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 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 jq( name = "merged", srcs = ["foo.json", "bar.json"], filter_file = "filter.txt", args = ["--slurp"], out = "foobar.json", ) # Convert genquery output to json 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)) }", ) # With --stamp, causes properties to be replaced by version control info. 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.BUILD_EMBED_LABEL // \"\")", ]), ) ``` You could also use it directly from a `genrule` by referencing the toolchain, and the `JQ_BIN` "Make variable" it exposes: ``` genrule( name = "case_genrule", srcs = ["a.json"], outs = ["genrule_output.json"], cmd = "$(JQ_BIN) '.' $(location a.json) > $@", toolchains = ["@jq_toolchains//:resolved_toolchain"], ) ``` Args: name: Name of the rule srcs: List of input files. May be empty. 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. filter_file: File containing filter expression (alternative to `filter`) args: Additional args to pass to jq out: Name of the output json file; defaults to the rule name plus ".json" **kwargs: Other common named parameters such as `tags` or `visibility` """ default_name = name + ".json" if not out and not default_name in srcs: out = default_name _jq_rule( name = name, srcs = srcs, filter = filter, filter_file = filter_file, args = args, out = out, **kwargs )