cafkafk/exercism
cafkafk/exercism
1
1
Fork 0
Code Activity

feat: grade-stat

Browse source
This commit is contained in:
Christina Sørensen 2024-12-06 16:14:02 +01:00
parent 6b317e935d
commit e20eb8b4c4
Signed by: cafkafk
GPG key ID: 26C542FD97F965CE
10 changed files with 1105 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

20
jq/grade-stats/.exercism/config.json Normal file
View file

@ -0,0 +1,20 @@
{
"authors": [
"glennj"
],
"files": {
"solution": [
"grade-stats.jq"
],
"test": [
"test-grade-stats.bats"
],
"exemplar": [
".meta/exemplar.jq"
],
"editor": [
"grades.json"
]
},
"blurb": "Demonstrate the reduce filter in jq"
}

1
jq/grade-stats/.exercism/metadata.json Normal file
View file

@ -0,0 +1 @@
{"track":"jq","exercise":"grade-stats","id":"8a64b3831a124a5ba7c5f7fffc62783d","url":"https://exercism.org/tracks/jq/exercises/grade-stats","handle":"cafkafk","is_requester":true,"auto_approve":false}

114
jq/grade-stats/HELP.md Normal file
View file

@ -0,0 +1,114 @@
# Help
## Running the tests
Each exercise contains a test file.
Run the tests using the `bats` program.
```bash
bats test-hello-world.bats
```
`bats` will need to be installed.
See the [Testing on the Bash track][bash] page for instructions to install `bats` for your system.
### bats is implemented in bash
The bats file is a bash script, with some special functions recognized by the `bats` command.
You'll see some tests that look like
```sh
jq -f some-exercise.jq <<< "{some,json,here}"
```
That `<<<` syntax is a bash [Here String][here-string].
It sends the string on the right-hand side into the standard input of the program on the left-hand side.
It is ([approximately][so]) the same as
```sh
echo "{some,json,here}" | jq -f some-exercise.jq
```
## Help for assert functions
The tests use functions from the [bats-assert][bats-assert] library.
Help for the various `assert*` functions can be found there.
## Skipped tests
Solving an exercise means making all its tests pass.
By default, only one test (the first one) is executed when you run the tests.
This is intentional, as it allows you to focus on just making that one test pass.
Once it passes, you can enable the next test by commenting out or removing the
[[ $BATS_RUN_SKIPPED == true ]] || skip
annotations prepending other tests.
## Overriding skips
To run all tests, including the ones with `skip` annotations, you can run:
```bash
BATS_RUN_SKIPPED=true bats test-some-exercise.bats
```
It can be convenient to use a wrapper function to save on typing: in `bash` you can do:
```bash
bats() {
BATS_RUN_SKIPPED=true command bats *.bats
}
```
Then run tests with just:
```bash
bats
```
## Debugging in `jq`
`jq` comes with a handy [`debug`][debug] filter.
Use it while you are developing your exercise solutions to inspect the data that is currently in the jq pipline.
See the [debugging doc][debugging] for more details.
[bash]: https://exercism.org/docs/tracks/bash/tests
[bats-assert]: https://github.com/bats-core/bats-assert
[here-string]: https://www.gnu.org/software/bash/manual/bash.html#Here-Strings
[so]: https://unix.stackexchange.com/a/80372/4667
[debug]: https://jqlang.github.io/jq/manual/v1.7/#debug
[debugging]: https://exercism.org/docs/tracks/jq/debugging
## Submitting your solution
You can submit your solution using the `exercism submit grade-stats.jq` command.
This command will upload your solution to the Exercism website and print the solution page's URL.
It's possible to submit an incomplete solution which allows you to:
- See how others have completed the exercise
- Request help from a mentor
## Need to get help?
If you'd like help solving the exercise, check the following pages:
- The [jq track's documentation](https://exercism.org/docs/tracks/jq)
- The [jq track's programming category on the forum](https://forum.exercism.org/c/programming/jq)
- [Exercism's programming category on the forum](https://forum.exercism.org/c/programming/5)
- The [Frequently Asked Questions](https://exercism.org/docs/using/faqs)
Should those resources not suffice, you could submit your (incomplete) solution to request mentoring.
## Need more help?
- Go to the [Exercism Community forum](https://forum.exercism.org) to get support and ask questions (or just chat!)
- Use the [Exercism Support](https://forum.exercism.org/c/support/8) category if you face any issues with working in the web editor, or downloading or submitting your exercises locally.
- Use the [Programming:jq](https://forum.exercism.org/c/programming/jq/133) category for jq-specific topics.
- Join the community on [Exercism's Discord server](https://exercism.org/r/discord).
- [StackOverflow](https://stackoverflow.com/questions/tagged/jq) can be used to search for your problem and see if it has been answered already.
You can also ask and answer questions.
- [Github issue tracker](https://github.com/exercism/jq/issues) is where we track our development and maintainance of `jq` exercises in exercism.
If none of the above links help you, feel free to post an issue here.

16
jq/grade-stats/HINTS.md Normal file
View file

@ -0,0 +1,16 @@
# Hints
## 1. Translate a numeric grade to a letter grade
- Use an [`if-then-else` expression][jq-man-if] with as many `elif` branches as needed.
## 2. Count the number of students for each letter grade
- The `reduce` filter needs a _stream_ to iterate over.
The input is an object.
Use the `to_entries` expression to transform the object into an array.
- The result object must have all the possible letter grades as keys, even if no students earned that grade.
- The [`+=` assignment][jq-man-arith-assign] will be useful.
[jq-man-if]: https://jqlang.github.io/jq/manual/v1.7/#if-then-else-end
[jq-man-arith-assign]: https://jqlang.github.io/jq/manual/v1.7/#arithmetic-update-assignment

153
jq/grade-stats/README.md Normal file
View file

@ -0,0 +1,153 @@
# Grade Stats
Welcome to Grade Stats on Exercism's jq Track.
If you need help running the tests or submitting your code, check out `HELP.md`.
If you get stuck on the exercise, check out `HINTS.md`, but try and solve it without using those first :)
## Introduction
## Reduce
Suppose we want to sum an array of numbers.
There are many ways to accomplish this goal.
- In many languages, this problem is expressed as a loop with an accumulator variable.
- This problem can be written as a recursive function.
In pseudo-code, we might have this.
```none
function Add(X, Sum=0):
if X is empty then
return Sum
else
return Add(rest(X), Sum + first(X))
end
end
```
This method of dividing the problem into smaller pieces can also be described as "reducing towards the base case."
**Reduce** is a way to combine all the elements of a data structure into a single value.
The process iterates over the data structure, applying a function to each element to update the accumulated result.
In `jq`, this process is implemented in the [`reduce` filter][jq-man-reduce].
In other languages, it might be called "fold", "fold-left", "inject", or "aggregate".
The `jq` `reduce` expression looks like this.
```jq
reduce STREAM_EXPRESSION as $var (INITIAL_VALUE; UPDATE_EXPRESSION)
```
- `STREAM_EXPRESSION` is a _stream_ of items, each stored in the `$var` variable in turn.
- Recall, to stream an array, use the [iterator filter `.[]`][jq-man-iterator]: `$myArray | .[]`.
- `INITIAL_VALUE` is the starting value of the accumulated result (known as the "accumulator").
- The `UPDATE_EXPRESSION` combines ("folds") the current value ($var) into the accumulator.
- In the context of this expression, `.` is the value of the accumulator.
- The output of the expression is stored into the accumulator for use in the next iteration.
- After the last iteration, the accumulated result is the output of `reduce`.
Let's look at an example: adding up the numbers in an array.
The `add` filter does just this, but we'll see how to implement it.
If we use `[10, 20, 30, 40]` as the input, and taking zero as the initial state, this is what each step looks like.
| \# | state | element | reducer | result |
| :-: | :---: | :-----: | :-----: | :----: |
| 1 | 0 | 10 | 0 + 10 | 10 |
| 2 | 10 | 20 | 10 + 20 | 30 |
| 3 | 30 | 30 | 30 + 30 | 60 |
| 4 | 60 | 40 | 60 + 40 | 100 |
In `jq` syntax, this looks like this code.
```jq
0 + 10 | . + 20 | . + 30 | . + 40
```
We can express that with the `reduce` filter.
```jq
[10, 20, 30, 40] | reduce .[] as $n (0; . + $n) # => 100
```
<!-- prettier-ignore -->
~~~~exercism/note
The `add` builtin is actually [implemented with `reduce`][jq-code-add], but uses "null" as the initial state (any data type can be added to null).
```jq
def add: reduce .[] as $x (null; . + $x);
```
[jq-code-add]: https://github.com/jqlang/jq/blob/jq-1.7/src/builtin.jq#L11
~~~~
<!-- prettier-ignore-end -->
### Some things to keep in mind
- In the reducing expression, `.` is the accumulator.
If the input is some object that you need to reference inside the reducing function, you need to store it in a variable.
```jq
{"apple": 10, "banana": 16, "carrot": 4}
| . as $obj
| reduce (keys | .[]) as $key (0; . + $obj[$key]) # => 30
```
- The accumulator can be of any type of data.
For example you may want to reverse an array.
```jq
["A", "B", "C", "D"]
| reduce .[] as $elem ([]; [$elem] + .) # => ["D", "C", "B", "A"]
```
[jq-man-reduce]: https://jqlang.github.io/jq/manual/v1.7/#reduce
[jq-man-iterator]: https://jqlang.github.io/jq/manual/v1.7/#array-object-value-iterator
## Instructions
You are a teacher.
At the end of the year, you have generated a numeric grade for each of your students.
Now you need to translate that to a letter grade and count how many students have achieved each letter grade
## 1. Translate a numeric grade to a letter grade
The `letter_grade` function will take a numeric grade as input, and it will output the letter.
Use these ranges:
| Letter | Grade |
| :----: | ---------: |
| A | 90% - 100% |
| B | 80% - 89% |
| C | 70% - 79% |
| D | 60% - 69% |
| F | 0% - 59% |
Example:
```jq
75 | letter_grade # => "C"
```
## 2. Count the number of students for each letter grade
The function `count_letter_grades` will take an object mapping student names to their grades.
The output will be an object mapping each letter grade to the number of students with that grade.
Example:
```jq
{"Joe": 78, "Jane": 93, "Richard": 72} | count_letter_grades
# => {"A": 1, "B": 0, "C": 2, "D": 0, "F": 0}
```
There are a few different ways to solve this.
Use the `reduce` filter for practice.
## Source
### Created by
- @glennj

637
jq/grade-stats/bats-extra.bash Normal file
View file

@ -0,0 +1,637 @@
# This is the source code for bats-support and bats-assert, concatenated
# * https://github.com/bats-core/bats-support
# * https://github.com/bats-core/bats-assert
#
# Comments have been removed to save space. See the git repos for full source code.
############################################################
#
# bats-support - Supporting library for Bats test helpers
#
# Written in 2016 by Zoltan Tombol <zoltan dot tombol at gmail dot com>
#
# To the extent possible under law, the author(s) have dedicated all
# copyright and related and neighboring rights to this software to the
# public domain worldwide. This software is distributed without any
# warranty.
#
# You should have received a copy of the CC0 Public Domain Dedication
# along with this software. If not, see
# <http://creativecommons.org/publicdomain/zero/1.0/>.
#
fail() {
(( $# == 0 )) && batslib_err || batslib_err "$@"
return 1
}
batslib_is_caller() {
local -i is_mode_direct=1
# Handle options.
while (( $# > 0 )); do
case "$1" in
-i|--indirect) is_mode_direct=0; shift ;;
--) shift; break ;;
*) break ;;
esac
done
# Arguments.
local -r func="$1"
# Check call stack.
if (( is_mode_direct )); then
[[ $func == "${FUNCNAME[2]}" ]] && return 0
else
local -i depth
for (( depth=2; depth<${#FUNCNAME[@]}; ++depth )); do
[[ $func == "${FUNCNAME[$depth]}" ]] && return 0
done
fi
return 1
}
batslib_err() {
{ if (( $# > 0 )); then
echo "$@"
else
cat -
fi
} >&2
}
batslib_count_lines() {
local -i n_lines=0
local line
while IFS='' read -r line || [[ -n $line ]]; do
(( ++n_lines ))
done < <(printf '%s' "$1")
echo "$n_lines"
}
batslib_is_single_line() {
for string in "$@"; do
(( $(batslib_count_lines "$string") > 1 )) && return 1
done
return 0
}
batslib_get_max_single_line_key_width() {
local -i max_len=-1
while (( $# != 0 )); do
local -i key_len="${#1}"
batslib_is_single_line "$2" && (( key_len > max_len )) && max_len="$key_len"
shift 2
done
echo "$max_len"
}
batslib_print_kv_single() {
local -ir col_width="$1"; shift
while (( $# != 0 )); do
printf '%-*s : %s\n' "$col_width" "$1" "$2"
shift 2
done
}
batslib_print_kv_multi() {
while (( $# != 0 )); do
printf '%s (%d lines):\n' "$1" "$( batslib_count_lines "$2" )"
printf '%s\n' "$2"
shift 2
done
}
batslib_print_kv_single_or_multi() {
local -ir width="$1"; shift
local -a pairs=( "$@" )
local -a values=()
local -i i
for (( i=1; i < ${#pairs[@]}; i+=2 )); do
values+=( "${pairs[$i]}" )
done
if batslib_is_single_line "${values[@]}"; then
batslib_print_kv_single "$width" "${pairs[@]}"
else
local -i i
for (( i=1; i < ${#pairs[@]}; i+=2 )); do
pairs[$i]="$( batslib_prefix < <(printf '%s' "${pairs[$i]}") )"
done
batslib_print_kv_multi "${pairs[@]}"
fi
}
batslib_prefix() {
local -r prefix="${1:- }"
local line
while IFS='' read -r line || [[ -n $line ]]; do
printf '%s%s\n' "$prefix" "$line"
done
}
batslib_mark() {
local -r symbol="$1"; shift
# Sort line numbers.
set -- $( sort -nu <<< "$( printf '%d\n' "$@" )" )
local line
local -i idx=0
while IFS='' read -r line || [[ -n $line ]]; do
if (( ${1:--1} == idx )); then
printf '%s\n' "${symbol}${line:${#symbol}}"
shift
else
printf '%s\n' "$line"
fi
(( ++idx ))
done
}
batslib_decorate() {
echo
echo "-- $1 --"
cat -
echo '--'
echo
}
############################################################
assert() {
if ! "$@"; then
batslib_print_kv_single 10 'expression' "$*" \
| batslib_decorate 'assertion failed' \
| fail
fi
}
assert_equal() {
if [[ $1 != "$2" ]]; then
batslib_print_kv_single_or_multi 8 \
'expected' "$2" \
'actual' "$1" \
| batslib_decorate 'values do not equal' \
| fail
fi
}
assert_failure() {
: "${output?}"
: "${status?}"
(( $# > 0 )) && local -r expected="$1"
if (( status == 0 )); then
batslib_print_kv_single_or_multi 6 'output' "$output" \
| batslib_decorate 'command succeeded, but it was expected to fail' \
| fail
elif (( $# > 0 )) && (( status != expected )); then
{ local -ir width=8
batslib_print_kv_single "$width" \
'expected' "$expected" \
'actual' "$status"
batslib_print_kv_single_or_multi "$width" \
'output' "$output"
} \
| batslib_decorate 'command failed as expected, but status differs' \
| fail
fi
}
assert_line() {
local -i is_match_line=0
local -i is_mode_partial=0
local -i is_mode_regexp=0
: "${lines?}"
# Handle options.
while (( $# > 0 )); do
case "$1" in
-n|--index)
if (( $# < 2 )) || ! [[ $2 =~ ^([0-9]|[1-9][0-9]+)$ ]]; then
echo "\`--index' requires an integer argument: \`$2'" \
| batslib_decorate 'ERROR: assert_line' \
| fail
return $?
fi
is_match_line=1
local -ri idx="$2"
shift 2
;;
-p|--partial) is_mode_partial=1; shift ;;
-e|--regexp) is_mode_regexp=1; shift ;;
--) shift; break ;;
*) break ;;
esac
done
if (( is_mode_partial )) && (( is_mode_regexp )); then
echo "\`--partial' and \`--regexp' are mutually exclusive" \
| batslib_decorate 'ERROR: assert_line' \
| fail
return $?
fi
# Arguments.
local -r expected="$1"
if (( is_mode_regexp == 1 )) && [[ '' =~ $expected ]] || (( $? == 2 )); then
echo "Invalid extended regular expression: \`$expected'" \
| batslib_decorate 'ERROR: assert_line' \
| fail
return $?
fi
# Matching.
if (( is_match_line )); then
# Specific line.
if (( is_mode_regexp )); then
if ! [[ ${lines[$idx]} =~ $expected ]]; then
batslib_print_kv_single 6 \
'index' "$idx" \
'regexp' "$expected" \
'line' "${lines[$idx]}" \
| batslib_decorate 'regular expression does not match line' \
| fail
fi
elif (( is_mode_partial )); then
if [[ ${lines[$idx]} != *"$expected"* ]]; then
batslib_print_kv_single 9 \
'index' "$idx" \
'substring' "$expected" \
'line' "${lines[$idx]}" \
| batslib_decorate 'line does not contain substring' \
| fail
fi
else
if [[ ${lines[$idx]} != "$expected" ]]; then
batslib_print_kv_single 8 \
'index' "$idx" \
'expected' "$expected" \
'actual' "${lines[$idx]}" \
| batslib_decorate 'line differs' \
| fail
fi
fi
else
# Contained in output.
if (( is_mode_regexp )); then
local -i idx
for (( idx = 0; idx < ${#lines[@]}; ++idx )); do
[[ ${lines[$idx]} =~ $expected ]] && return 0
done
{ local -ar single=( 'regexp' "$expected" )
local -ar may_be_multi=( 'output' "$output" )
local -ir width="$( batslib_get_max_single_line_key_width "${single[@]}" "${may_be_multi[@]}" )"
batslib_print_kv_single "$width" "${single[@]}"
batslib_print_kv_single_or_multi "$width" "${may_be_multi[@]}"
} \
| batslib_decorate 'no output line matches regular expression' \
| fail
elif (( is_mode_partial )); then
local -i idx
for (( idx = 0; idx < ${#lines[@]}; ++idx )); do
[[ ${lines[$idx]} == *"$expected"* ]] && return 0
done
{ local -ar single=( 'substring' "$expected" )
local -ar may_be_multi=( 'output' "$output" )
local -ir width="$( batslib_get_max_single_line_key_width "${single[@]}" "${may_be_multi[@]}" )"
batslib_print_kv_single "$width" "${single[@]}"
batslib_print_kv_single_or_multi "$width" "${may_be_multi[@]}"
} \
| batslib_decorate 'no output line contains substring' \
| fail
else
local -i idx
for (( idx = 0; idx < ${#lines[@]}; ++idx )); do
[[ ${lines[$idx]} == "$expected" ]] && return 0
done
{ local -ar single=( 'line' "$expected" )
local -ar may_be_multi=( 'output' "$output" )
local -ir width="$( batslib_get_max_single_line_key_width "${single[@]}" "${may_be_multi[@]}" )"
batslib_print_kv_single "$width" "${single[@]}"
batslib_print_kv_single_or_multi "$width" "${may_be_multi[@]}"
} \
| batslib_decorate 'output does not contain line' \
| fail
fi
fi
}
assert_output() {
local -i is_mode_partial=0
local -i is_mode_regexp=0
local -i is_mode_nonempty=0
local -i use_stdin=0
: "${output?}"
# Handle options.
if (( $# == 0 )); then
is_mode_nonempty=1
fi
while (( $# > 0 )); do
case "$1" in
-p|--partial) is_mode_partial=1; shift ;;
-e|--regexp) is_mode_regexp=1; shift ;;
-|--stdin) use_stdin=1; shift ;;
--) shift; break ;;
*) break ;;
esac
done
if (( is_mode_partial )) && (( is_mode_regexp )); then
echo "\`--partial' and \`--regexp' are mutually exclusive" \
| batslib_decorate 'ERROR: assert_output' \
| fail
return $?
fi
# Arguments.
local expected
if (( use_stdin )); then
expected="$(cat -)"
else
expected="${1-}"
fi
# Matching.
if (( is_mode_nonempty )); then
if [ -z "$output" ]; then
echo 'expected non-empty output, but output was empty' \
| batslib_decorate 'no output' \
| fail
fi
elif (( is_mode_regexp )); then
if [[ '' =~ $expected ]] || (( $? == 2 )); then
echo "Invalid extended regular expression: \`$expected'" \
| batslib_decorate 'ERROR: assert_output' \
| fail
elif ! [[ $output =~ $expected ]]; then
batslib_print_kv_single_or_multi 6 \
'regexp' "$expected" \
'output' "$output" \
| batslib_decorate 'regular expression does not match output' \
| fail
fi
elif (( is_mode_partial )); then
if [[ $output != *"$expected"* ]]; then
batslib_print_kv_single_or_multi 9 \
'substring' "$expected" \
'output' "$output" \
| batslib_decorate 'output does not contain substring' \
| fail
fi
else
if [[ $output != "$expected" ]]; then
batslib_print_kv_single_or_multi 8 \
'expected' "$expected" \
'actual' "$output" \
| batslib_decorate 'output differs' \
| fail
fi
fi
}
assert_success() {
: "${output?}"
: "${status?}"
if (( status != 0 )); then
{ local -ir width=6
batslib_print_kv_single "$width" 'status' "$status"
batslib_print_kv_single_or_multi "$width" 'output' "$output"
} \
| batslib_decorate 'command failed' \
| fail
fi
}
refute() {
if "$@"; then
batslib_print_kv_single 10 'expression' "$*" \
| batslib_decorate 'assertion succeeded, but it was expected to fail' \
| fail
fi
}
refute_line() {
local -i is_match_line=0
local -i is_mode_partial=0
local -i is_mode_regexp=0
: "${lines?}"
# Handle options.
while (( $# > 0 )); do
case "$1" in
-n|--index)
if (( $# < 2 )) || ! [[ $2 =~ ^([0-9]|[1-9][0-9]+)$ ]]; then
echo "\`--index' requires an integer argument: \`$2'" \
| batslib_decorate 'ERROR: refute_line' \
| fail
return $?
fi
is_match_line=1
local -ri idx="$2"
shift 2
;;
-p|--partial) is_mode_partial=1; shift ;;
-e|--regexp) is_mode_regexp=1; shift ;;
--) shift; break ;;
*) break ;;
esac
done
if (( is_mode_partial )) && (( is_mode_regexp )); then
echo "\`--partial' and \`--regexp' are mutually exclusive" \
| batslib_decorate 'ERROR: refute_line' \
| fail
return $?
fi
# Arguments.
local -r unexpected="$1"
if (( is_mode_regexp == 1 )) && [[ '' =~ $unexpected ]] || (( $? == 2 )); then
echo "Invalid extended regular expression: \`$unexpected'" \
| batslib_decorate 'ERROR: refute_line' \
| fail
return $?
fi
# Matching.
if (( is_match_line )); then
# Specific line.
if (( is_mode_regexp )); then
if [[ ${lines[$idx]} =~ $unexpected ]]; then
batslib_print_kv_single 6 \
'index' "$idx" \
'regexp' "$unexpected" \
'line' "${lines[$idx]}" \
| batslib_decorate 'regular expression should not match line' \
| fail
fi
elif (( is_mode_partial )); then
if [[ ${lines[$idx]} == *"$unexpected"* ]]; then
batslib_print_kv_single 9 \
'index' "$idx" \
'substring' "$unexpected" \
'line' "${lines[$idx]}" \
| batslib_decorate 'line should not contain substring' \
| fail
fi
else
if [[ ${lines[$idx]} == "$unexpected" ]]; then
batslib_print_kv_single 5 \
'index' "$idx" \
'line' "${lines[$idx]}" \
| batslib_decorate 'line should differ' \
| fail
fi
fi
else
# Line contained in output.
if (( is_mode_regexp )); then
local -i idx
for (( idx = 0; idx < ${#lines[@]}; ++idx )); do
if [[ ${lines[$idx]} =~ $unexpected ]]; then
{ local -ar single=( 'regexp' "$unexpected" 'index' "$idx" )
local -a may_be_multi=( 'output' "$output" )
local -ir width="$( batslib_get_max_single_line_key_width "${single[@]}" "${may_be_multi[@]}" )"
batslib_print_kv_single "$width" "${single[@]}"
if batslib_is_single_line "${may_be_multi[1]}"; then
batslib_print_kv_single "$width" "${may_be_multi[@]}"
else
may_be_multi[1]="$( printf '%s' "${may_be_multi[1]}" | batslib_prefix | batslib_mark '>' "$idx" )"
batslib_print_kv_multi "${may_be_multi[@]}"
fi
} \
| batslib_decorate 'no line should match the regular expression' \
| fail
return $?
fi
done
elif (( is_mode_partial )); then
local -i idx
for (( idx = 0; idx < ${#lines[@]}; ++idx )); do
if [[ ${lines[$idx]} == *"$unexpected"* ]]; then
{ local -ar single=( 'substring' "$unexpected" 'index' "$idx" )
local -a may_be_multi=( 'output' "$output" )
local -ir width="$( batslib_get_max_single_line_key_width "${single[@]}" "${may_be_multi[@]}" )"
batslib_print_kv_single "$width" "${single[@]}"
if batslib_is_single_line "${may_be_multi[1]}"; then
batslib_print_kv_single "$width" "${may_be_multi[@]}"
else
may_be_multi[1]="$( printf '%s' "${may_be_multi[1]}" | batslib_prefix | batslib_mark '>' "$idx" )"
batslib_print_kv_multi "${may_be_multi[@]}"
fi
} \
| batslib_decorate 'no line should contain substring' \
| fail
return $?
fi
done
else
local -i idx
for (( idx = 0; idx < ${#lines[@]}; ++idx )); do
if [[ ${lines[$idx]} == "$unexpected" ]]; then
{ local -ar single=( 'line' "$unexpected" 'index' "$idx" )
local -a may_be_multi=( 'output' "$output" )
local -ir width="$( batslib_get_max_single_line_key_width "${single[@]}" "${may_be_multi[@]}" )"
batslib_print_kv_single "$width" "${single[@]}"
if batslib_is_single_line "${may_be_multi[1]}"; then
batslib_print_kv_single "$width" "${may_be_multi[@]}"
else
may_be_multi[1]="$( printf '%s' "${may_be_multi[1]}" | batslib_prefix | batslib_mark '>' "$idx" )"
batslib_print_kv_multi "${may_be_multi[@]}"
fi
} \
| batslib_decorate 'line should not be in output' \
| fail
return $?
fi
done
fi
fi
}
refute_output() {
local -i is_mode_partial=0
local -i is_mode_regexp=0
local -i is_mode_empty=0
local -i use_stdin=0
: "${output?}"
# Handle options.
if (( $# == 0 )); then
is_mode_empty=1
fi
while (( $# > 0 )); do
case "$1" in
-p|--partial) is_mode_partial=1; shift ;;
-e|--regexp) is_mode_regexp=1; shift ;;
-|--stdin) use_stdin=1; shift ;;
--) shift; break ;;
*) break ;;
esac
done
if (( is_mode_partial )) && (( is_mode_regexp )); then
echo "\`--partial' and \`--regexp' are mutually exclusive" \
| batslib_decorate 'ERROR: refute_output' \
| fail
return $?
fi
# Arguments.
local unexpected
if (( use_stdin )); then
unexpected="$(cat -)"
else
unexpected="${1-}"
fi
if (( is_mode_regexp == 1 )) && [[ '' =~ $unexpected ]] || (( $? == 2 )); then
echo "Invalid extended regular expression: \`$unexpected'" \
| batslib_decorate 'ERROR: refute_output' \
| fail
return $?
fi
# Matching.
if (( is_mode_empty )); then
if [ -n "$output" ]; then
batslib_print_kv_single_or_multi 6 \
'output' "$output" \
| batslib_decorate 'output non-empty, but expected no output' \
| fail
fi
elif (( is_mode_regexp )); then
if [[ $output =~ $unexpected ]]; then
batslib_print_kv_single_or_multi 6 \
'regexp' "$unexpected" \
'output' "$output" \
| batslib_decorate 'regular expression should not match output' \
| fail
fi
elif (( is_mode_partial )); then
if [[ $output == *"$unexpected"* ]]; then
batslib_print_kv_single_or_multi 9 \
'substring' "$unexpected" \
'output' "$output" \
| batslib_decorate 'output should not contain substring' \
| fail
fi
else
if [[ $output == "$unexpected" ]]; then
batslib_print_kv_single_or_multi 6 \
'output' "$output" \
| batslib_decorate 'output equals, but it was expected to differ' \
| fail
fi
fi
}

29
jq/grade-stats/bats-jq.bash Normal file
View file

@ -0,0 +1,29 @@
#!/usr/bin/env bash
#
# `bats-core` will consume both stdout and stderr for the `run` command's output.
# However `jq` prints its DEBUG output on stderr.
#
# Lines starting with `["DEBUG:",` will be prefixed with a hash and printed on file descriptor 3.
# Other lines on stderr will remain on stderr for bats to consume.
#
# See `bats-core` docs:
# - "Printing to the terminal", https://bats-core.readthedocs.io/en/stable/writing-tests.html#printing-to-the-terminal
# - "File descriptor 3", https://bats-core.readthedocs.io/en/stable/writing-tests.html#file-descriptor-3-read-this-if-bats-hangs
jq() {
local output stderr rc line
stderr=$(mktemp)
output=$(command jq "$@" 2> "$stderr")
rc=$?
while IFS= read -r line || [[ -n $line ]]; do
if [[ $line == '["DEBUG:",'* ]]; then
echo "# $line" >&3
else
echo "$line" >&2
fi
done < "$stderr"
rm -f "$stderr"
echo "$output"
return "$rc"
}

25
jq/grade-stats/grade-stats.jq Normal file
View file

@ -0,0 +1,25 @@
# Given a numeric score between 0 and 100, output a letter grade
# - "A" is 90% - 100%
# - "B" is 80% - 89%
# - "C" is 70% - 79%
# - "D" is 60% - 69%
# - "F" is 0% - 59%
def letter_grade:
if . < 60 then "F"
elif . < 70 then "D"
elif . < 80 then "C"
elif . < 90 then "B"
else "A"
end;
# Given an object that maps a student's name to their grade,
# generate an object that maps the letter grade to the number of
# students with that grade
def count_letter_grades:
reduce .[] as $s (
{A: 0, B: 0, C: 0, D: 0, F: 0};
.[$s | letter_grade] += 1
);

22
jq/grade-stats/grades.json Normal file
View file

@ -0,0 +1,22 @@
{
"Alexandra": 99,
"Beatrice": 74,
"Bethany": 100,
"Brian": 97,
"Clinton": 54,
"Emerson": 86,
"Evan": 72,
"Grady": 70,
"Jane": 52,
"Joanna": 76,
"Kim": 75,
"Lorraine": 48,
"Marcy": 96,
"Raphael": 67,
"Raymond": 61,
"Reynaldo": 98,
"Shelia": 78,
"Staci": 59,
"Sybil": 57,
"Taylor": 92
}

88
jq/grade-stats/test-grade-stats.bats Normal file
View file

@ -0,0 +1,88 @@
#!/usr/bin/env bats
load bats-extra
load bats-jq
assert_key_value() {
local key=$1 expected=$2 actual
actual=$(jq -rc --arg key "$key" '.[$key]' <<< "$output")
assert_equal "$actual" "$expected"
}
@test 'number to letter grade A' {
## task 1
run jq -nc '
include "grade-stats";
[ range(90; 101) | letter_grade ]
'
assert_success
assert_output '["A","A","A","A","A","A","A","A","A","A","A"]'
}
@test 'number to letter grade B' {
## task 1
run jq -nc '
include "grade-stats";
[ range(80; 90) | letter_grade ]
'
assert_success
assert_output '["B","B","B","B","B","B","B","B","B","B"]'
}
@test 'number to letter grade C' {
## task 1
run jq -nc '
include "grade-stats";
[ range(70; 80) | letter_grade ]
'
assert_success
assert_output '["C","C","C","C","C","C","C","C","C","C"]'
}
@test 'number to letter grade D' {
## task 1
run jq -nc '
include "grade-stats";
[ range(60; 70) | letter_grade ]
'
assert_success
assert_output '["D","D","D","D","D","D","D","D","D","D"]'
}
@test 'number to letter grade F' {
## task 1
run jq -nc '
include "grade-stats";
[ range(0; 60) | letter_grade ]
| (length == 60 and all(. == "F"))
'
assert_success
assert_output 'true'
}
@test 'aggregate the number of students by letter grade' {
## task 2
run jq -c '
include "grade-stats";
count_letter_grades
' grades.json
assert_success
assert_key_value "A" 6 "$output"
assert_key_value "B" 1 "$output"
assert_key_value "C" 6 "$output"
assert_key_value "D" 2 "$output"
assert_key_value "F" 5 "$output"
}
@test 'aggregate, all letter grades are present even if zero students' {
## task 2
run jq -c '
include "grade-stats";
count_letter_grades
' <<< '{"alpha": 95, "bravo": 88}'
assert_success
assert_key_value "A" 1 "$output"
assert_key_value "B" 1 "$output"
assert_key_value "C" 0 "$output"
assert_key_value "D" 0 "$output"
assert_key_value "F" 0 "$output"
}