port: allergies

config.json

@@ -357,6 +357,17 @@
         "math",
         "transforming"
       ]
+    },
+    {
+      "slug": "allergies",
+      "uuid": "b572a9d9-859d-43bd-a8e1-8d6f7566b685",
+      "core": false,
+      "unlocked_by": "luhn",
+      "difficulty": 2,
+      "topics": [
+        "bitwise_operations",
+        "arrays"
+      ]
     }
   ]
 }

exercises/allergies/.meta/version

@@ -0,0 +1 @@
+2.0.0

exercises/allergies/README.md

@@ -0,0 +1,56 @@
+# Allergies
+
+Given a person's allergy score, determine whether or not they're allergic to a given item, and their full list of allergies.
+
+An allergy test produces a single numeric score which contains the
+information about all the allergies the person has (that they were
+tested for).
+
+The list of items (and their value) that were tested are:
+
+* eggs (1)
+* peanuts (2)
+* shellfish (4)
+* strawberries (8)
+* tomatoes (16)
+* chocolate (32)
+* pollen (64)
+* cats (128)
+
+So if Tom is allergic to peanuts and chocolate, he gets a score of 34.
+
+Now, given just that score of 34, your program should be able to say:
+
+- Whether Tom is allergic to any one of those allergens listed above.
+- All the allergens Tom is allergic to.
+
+Note: a given score may include allergens **not** listed above (i.e.
+allergens that score 256, 512, 1024, etc.).  Your program should
+ignore those components of the score.  For example, if the allergy
+score is 257, your program should only report the eggs (1) allergy.
+
+
+Run the tests with:
+
+```bash
+bats allergies_test.sh
+```
+
+After the first test(s) pass, continue by commenting out or removing the `skip` annotations prepending other tests.
+
+## Source
+
+Jumpstart Lab Warm-up [http://jumpstartlab.com](http://jumpstartlab.com)
+
+
+## External utilities
+`Bash` is a language to write scripts that works closely with various system utilities,
+like [`sed`](https://www.gnu.org/software/sed/), [`awk`](https://www.gnu.org/software/gawk/), [`date`](https://www.gnu.org/software/coreutils/manual/html_node/date-invocation.html) and even other programming languages, like [`Python`](https://www.python.org/).
+This track does not restrict the usage of these utilities, and as long as your solution is portable
+between systems and does not require installing third party applications, feel free to use them to solve the exercise.
+
+For an extra challenge, if you would like to have a better understanding of the language,
+try to re-implement the solution in pure `Bash`, without using any external tools.
+
+## Submitting Incomplete Solutions
+It's possible to submit an incomplete solution so you can see how others have completed the exercise.

exercises/allergies/allergies_test.sh

@@ -0,0 +1,113 @@
+#!/usr/bin/env bash
+
+@test 'no_allergies_means_not_allergic' {
+    #skip
+    run bash allergies.sh 0 allergic_to peanuts
+    [[ $status -eq 0 ]] 
+    [[ $output = "false" ]]
+    run bash allergies.sh 0 allergic_to cats
+    [[ $status -eq 0 ]] 
+    [[ $output = "false" ]]
+    run bash allergies.sh 0 allergic_to strawberries
+    [[ $status -eq 0 ]] 
+    [[ $output = "false" ]]
+}
+
+@test 'is_allergic_to_eggs' {
+    skip 
+    run bash allergies.sh 1 allergic_to eggs
+    [[ $status -eq 0 ]]
+    [[ $output = "true" ]]
+}
+
+@test 'allergic_to_eggs_in_addition_to_other_stuff' {
+    skip 
+    run bash allergies.sh 5 allergic_to eggs
+    [[ $status -eq 0 ]]
+    [[ $output = "true" ]]
+    run bash allergies.sh 5 allergic_to shellfish
+    [[ $status -eq 0 ]]
+    [[ $output = "true" ]]
+    run bash allergies.sh 5 allergic_to strawberries
+    [[ $status -eq 0 ]] 
+    [[ $output = "false" ]]
+}
+
+@test 'allergic_to_strawberries_but_not_peanuts' {
+    skip 
+    run bash allergies.sh 9 allergic_to eggs
+    [[ $status -eq 0 ]]
+    [[ $output = "true" ]]
+    run bash allergies.sh 9 allergic_to peanuts
+    [[ $status -eq 0 ]] 
+    [[ $output = "false" ]]
+    run bash allergies.sh 9 allergic_to shellfish
+    [[ $status -eq 0 ]] 
+    [[ $output = "false" ]]
+    run bash allergies.sh 9 allergic_to strawberries
+    [[ $status -eq 0 ]]
+    [[ $output = "true" ]]
+}
+
+@test 'no_allergies_at_all' {
+    skip 
+    run bash allergies.sh 0 list
+    [[ $status -eq 0 ]]
+    [[ $output == "" ]]
+}
+
+@test 'allergic_to_just_eggs' {
+    skip 
+    run bash allergies.sh 1 list
+    [[ $status -eq 0 ]]
+    [[ $output == "eggs" ]]
+}
+
+@test 'allergic_to_just_peanuts' {
+    skip 
+    run bash allergies.sh 2 list
+    [[ $status -eq 0 ]]
+    [[ $output == "peanuts" ]]
+}
+
+@test 'allergic_to_just_strawberries' {
+    skip 
+    run bash allergies.sh 8 list
+    [[ $status -eq 0 ]]
+    [[ $output == "strawberries" ]]
+}
+
+@test 'allergic_to_eggs_and_peanuts' {
+    skip 
+    run bash allergies.sh 3 list
+    [[ $status -eq 0 ]]
+    [[ $output == "eggs peanuts" ]]
+}
+
+@test 'allergic_to_more_than_eggs_but_not_peanuts' {
+    skip 
+    run bash allergies.sh 5 list
+    [[ $status -eq 0 ]]
+    [[ $output == "eggs shellfish" ]]
+}
+
+@test 'allergic_to_lots_of_stuff' {
+    skip 
+    run bash allergies.sh 248 list
+    [[ $status -eq 0 ]]
+    [[ $output == "strawberries tomatoes chocolate pollen cats" ]]
+}
+
+@test 'allergic_to_everything' {
+    skip 
+    run bash allergies.sh 255 list
+    [[ $status -eq 0 ]]
+    [[ $output == "eggs peanuts shellfish strawberries tomatoes chocolate pollen cats" ]]
+}
+
+@test 'ignore_non_allergen_score_parts' {
+    skip 
+    run bash allergies.sh 509 list
+    [[ $status -eq 0 ]]
+    [[ $output == "eggs shellfish strawberries tomatoes chocolate pollen cats" ]]
+}

exercises/allergies/example.sh

@@ -0,0 +1,72 @@
+#!/bin/bash
+
+allergens=(
+  eggs peanuts shellfish strawberries
+  tomatoes chocolate pollen cats
+)
+
+main() {
+    if (( $# < 2 )); then
+        echo "usage: ${0##*/} <code> list" >&2
+        echo "usage: ${0##*/} <code> allergic_to <allergen>" >&2
+        exit 255
+    fi
+
+    local code=$1
+    local cmd=$2
+
+    case $cmd in
+        list)
+            list_allergies "$code"
+            ;;
+        allergic_to)
+            if [[ -z "$3" ]]; then
+                echo "error: missing argument" >&2
+                exit 1
+            fi
+            is_allergic_to "$code" "$3"
+            ;;
+    esac
+}
+
+# returns a 0/1 exit status
+index_test() {
+    local code=$1 idx=$2
+    (( (code & (1 << idx)) != 0 ))
+}
+
+# print a space-separated list of allergens encoded by
+# the allergy code
+list_allergies() {
+    local code=$1
+    local allergies=()
+    local i
+    # iterate over the array _indices_
+    for i in "${!allergens[@]}"; do
+        if index_test "$code" "$i"; then
+            allergies+=( "${allergens[i]}" )
+        fi
+    done
+    echo "${allergies[*]}"
+}
+
+# print "true" if the allergy code includes the given allergen,
+# print "false" otherwise
+is_allergic_to() {
+    local code=$1
+    local allergen=$2
+    local i
+    # iterate over the array _indices_
+    for i in "${!allergens[@]}"; do
+        if  [[ ${allergens[i]} == "$allergen" ]] &&
+            index_test "$code" "$i"
+        then
+            echo "true"
+            exit
+        fi
+
+    done
+    echo "false"
+}
+
+main "$@"