Add install-didc script (#5624)

# Motivation

We have the same code to install `didc` in 5 different places.

# Changes

1. Add a script which can install `didc` on Mac or Linux.
2. Use it instead of the existing duplicated code.

# Tests

1. Ran manually on MacOS.
2. CI passes using the new script.

# Todos

- [ ] Add entry to changelog (if necessary).
not necessary

.github/workflows/checks.yml

@@ -130,13 +130,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - name: Install didc
-        run: |
-          USER_BIN="$HOME/.local/bin"
-          mkdir -p "$USER_BIN"
-          echo "$USER_BIN" >> $GITHUB_PATH
-          version="$(jq -r .defaults.build.config.DIDC_RELEASE dfx.json)"
-          # TODO: Make `didc` support `binstall`, then use `binstall` here.
-          curl -Lf "https://github.com/dfinity/candid/releases/download/${version}/didc-linux64" | install -m 755 /dev/stdin "$USER_BIN/didc"
+        run: scripts/install-didc
       - name: Check didc
         run: command -v didc
       - name: Run the ic_commit code generator for proposals
@@ -162,13 +156,7 @@ jobs:
         with:
           fetch-depth: 0
       - name: Install didc
-        run: |
-          USER_BIN="$HOME/.local/bin"
-          mkdir -p "$USER_BIN"
-          echo "$USER_BIN" >> $GITHUB_PATH
-          version="$(jq -r .defaults.build.config.DIDC_RELEASE dfx.json)"
-          # TODO: Use `binstall`, once `didc` supports it.
-          curl -Lf "https://github.com/dfinity/candid/releases/download/${version}/didc-linux64" | install -m 755 /dev/stdin "$USER_BIN/didc"
+        run: scripts/install-didc
       - name: Check didc
         run: command -v didc
       - name: Install dfx
@@ -217,13 +205,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - name: Install didc
-        run: |
-          USER_BIN="$HOME/.local/bin"
-          mkdir -p "$USER_BIN"
-          echo "$USER_BIN" >> $GITHUB_PATH
-          version="$(jq -r .defaults.build.config.DIDC_RELEASE dfx.json)"
-          # TODO: Make `didc` support `binstall`, then use `binstall` here.
-          curl -Lf "https://github.com/dfinity/candid/releases/download/${version}/didc-linux64" | install -m 755 /dev/stdin "$USER_BIN/didc"
+        run: scripts/install-didc
       - name: Install cargo binstall
         uses: ./.github/actions/install_binstall
       - name: Install idl2json

.github/workflows/update-aggregator.yml

@@ -16,13 +16,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - name: Install didc
-        run: |
-          USER_BIN="$HOME/.local/bin"
-          mkdir -p "$USER_BIN"
-          echo "$USER_BIN" >> $GITHUB_PATH
-          version="$(jq -r .defaults.build.config.DIDC_RELEASE dfx.json)"
-          # TODO: Make `didc` support `binstall`, then use `binstall` here.
-          curl -Lf "https://github.com/dfinity/candid/releases/download/${version}/didc-linux64" | install -m 755 /dev/stdin "$USER_BIN/didc"
+        run: scripts/install-didc
       - name: Find newer IC release, if any
         id: update
         run: |

.github/workflows/update-proposals.yml

@@ -16,13 +16,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - name: Install didc
-        run: |
-          USER_BIN="$HOME/.local/bin"
-          mkdir -p "$USER_BIN"
-          echo "$USER_BIN" >> $GITHUB_PATH
-          version="$(jq -r .defaults.build.config.DIDC_RELEASE dfx.json)"
-          # TODO: Make `didc` support `binstall`, then use `binstall` here.
-          curl -Lf "https://github.com/dfinity/candid/releases/download/${version}/didc-linux64" | install -m 755 /dev/stdin "$USER_BIN/didc"
+        run: scripts/install-didc
       - name: Find newer IC release, if any
         id: update
         run: |

scripts/install-didc

@@ -0,0 +1,33 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+SOURCE_DIR="$(dirname "$(realpath "${BASH_SOURCE[0]}")")"
+
+# Source the clap.bash file ---------------------------------------------------
+source "$SOURCE_DIR/clap.bash"
+# Define options
+clap.define short=r long=release desc="The didc release to install" variable=RELEASE default="pinned"
+# Source the output file ----------------------------------------------------------
+source "$(clap.build)"
+
+if [[ "${RELEASE:-}" == "pinned" ]]; then
+  RELEASE="$(jq -r '.defaults.build.config.DIDC_RELEASE' "$SOURCE_DIR/../dfx.json")"
+fi
+
+echo "Installing didc release $RELEASE"
+
+if [[ "$(uname)" == "Darwin" ]]; then
+  echo "Installing MacOS version"
+  DIDC_URL="https://github.com/dfinity/candid/releases/download/${RELEASE}/didc-macos"
+else
+  echo "Installing Linux version"
+  DIDC_URL="https://github.com/dfinity/candid/releases/download/${RELEASE}/didc-linux64"
+fi
+
+USER_BIN="$HOME/.local/bin"
+mkdir -p "$USER_BIN"
+tmpfile="$(mktemp)"
+curl -Lf "$DIDC_URL" >"$tmpfile"
+install -m 755 "$tmpfile" "$USER_BIN/didc"
+
+echo "Installed $("$USER_BIN/didc" --version)"