[fractal/fractal-next] scripts: Reorganize checks and prettify output

[Julian Sparber <jsparber src gnome org>]

commit 9f4ad6fcbfdfe4017e31e839e98b5af0d2fd04f3
Author: Kévin Commaille <zecakeh tedomum fr>
Date:   Fri Jan 14 23:23:32 2022 +0100

    scripts: Reorganize checks and prettify output

 scripts/checks.sh | 206 +++++++++++++++++++++++++++++++++++++++---------------
 1 file changed, 151 insertions(+), 55 deletions(-)
---
diff --git a/scripts/checks.sh b/scripts/checks.sh
index b7482b3f..15ccae72 100755
--- a/scripts/checks.sh
+++ b/scripts/checks.sh
@@ -21,9 +21,156 @@ ERROR CODES:
 EOF
 }
 
+# Style helpers
+act="\e[1;32m"
+err="\e[1;31m"
+pos="\e[32m"
+neg="\e[31m"
+res="\e[0m"
+
+# Common styled strings
+Installing="${act}Installing${res}"
+Checking="  ${act}Checking${res}"
+Failed="    ${err}Failed${res}"
+error="${err}error:${res}"
+invalid="${neg}Invalid input${res}"
+ok="${pos}ok${res}"
+fail="${neg}fail${res}"
+
 # Initialize variables
-verbose=0
 force_install=0
+verbose=0
+
+# Check if rustup is available.
+# Argument:
+#   '-i' to install if missing.
+check_rustup() {
+    if ! which rustup &> /dev/null; then
+        if [[ "$1" == '-i' ]]; then
+            echo -e "$Installing rustup…"
+            curl https://sh.rustup.rs -sSf  | sh -s -- -y
+            export PATH=$PATH:$HOME/.cargo/bin
+            if ! which rustup &> /dev/null; then
+                echo -e "$Failed to install rustup"
+                exit 2
+            fi
+        else
+            exit 2
+        fi
+    fi
+}
+
+# Install cargo via rustup.
+install_cargo() {
+    check_rustup -i
+    if ! which cargo >/dev/null 2>&1; then
+        echo -e "$Failed to install cargo"
+        exit 2
+    fi
+}
+
+# Check if cargo is available. If not, ask to install it.
+check_cargo() {
+    if ! which cargo >/dev/null 2>&1; then
+        echo "Unable to find cargo for pre-commit checks"
+
+        if [[ $force_install -eq 1 ]]; then
+            install_cargo
+        elif [ ! -t 1 ]; then
+            exit 2
+        elif check_rustup; then
+            echo -e "$error rustup is installed but the cargo command isn't available"
+            exit 2
+        else
+            echo ""
+            echo "y: Install cargo via rustup"
+            echo "N: Don't install cargo and abort checks"
+            echo ""
+            while true; do
+                echo -n "Install cargo? [y/N]: "; read yn < /dev/tty
+                case $yn in
+                    [Yy]* )
+                        install_cargo
+                        break
+                        ;;
+                    [Nn]* | "" )
+                        exit 2
+                        ;;
+                    * ) 
+                        echo $invalid
+                        ;;
+                esac
+            done
+        fi
+    fi
+
+    if [[ $verbose -eq 1 ]]; then
+        echo ""
+        rustc -Vv && cargo -Vv
+        echo ""
+    fi
+}
+
+# Install rustfmt with rustup.
+install_rustfmt() {
+    check_rustup -i
+
+    echo -e "$Installing rustfmt…"
+    rustup component add rustfmt
+    if ! cargo fmt --version >/dev/null 2>&1; then
+        echo -e "$Failed to install rustfmt"
+        exit 2
+    fi
+}
+
+# Run rustfmt to enforce code style.
+run_rustfmt() {
+    if ! cargo fmt --version >/dev/null 2>&1; then
+        echo "Unable to check Fractal’s code style, because rustfmt could not be run"
+
+        if [[ $force_install -eq 1 ]]; then
+            install_rustfmt
+        elif [ ! -t 1 ]; then
+            exit 2
+        else
+            echo ""
+            echo "y: Install rustfmt via rustup"
+            echo "N: Don't install rustfmt and abort checks"
+            echo ""
+            while true; do
+                echo -n "Install rustfmt? [y/N]: "; read yn < /dev/tty
+                case $yn in
+                    [Yy]* ) 
+                        install_rustfmt
+                        break
+                        ;;
+                    [Nn]* | "" )
+                        exit 2
+                        ;;
+                    * ) 
+                        echo $invalid
+                        ;;
+                esac
+            done
+        fi
+    fi
+    
+    echo -e "$Checking code style…"
+
+    if [[ $verbose -eq 1 ]]; then
+        echo ""
+        cargo fmt --version
+        echo ""
+    fi
+
+    if ! cargo fmt --all -- --check; then
+        echo -e "  Checking code style result: $fail"
+        echo "Please fix the above issues, either manually or by running: cargo fmt --all"
+        exit 1
+    else
+        echo -e "  Checking code style result: $ok"
+    fi
+}
 
 # Check arguments
 while [[ "$1" ]]; do case $1 in
@@ -42,57 +189,6 @@ while [[ "$1" ]]; do case $1 in
         exit 1
 esac; shift; done
 
-install_rustfmt() {
-    if ! which rustup &> /dev/null; then
-        curl https://sh.rustup.rs -sSf  | sh -s -- -y
-        export PATH=$PATH:$HOME/.cargo/bin
-        if ! which rustup &> /dev/null; then
-            echo "Failed to install rustup."
-            exit 2
-        fi
-    fi
-
-    echo "Installing rustfmt…"
-    rustup component add rustfmt
-}
-
-if ! which cargo >/dev/null 2>&1 || ! cargo fmt --help >/dev/null 2>&1; then
-    echo "Unable to check Fractal’s code style, because rustfmt could not be run."
-
-    if [[ $force_install -eq 1 ]]; then
-        install_rustfmt
-    elif [ ! -t 1 ]; then
-        # No input is possible
-        exit 2
-    else
-        echo ""
-        echo "y: Install rustfmt via rustup"
-        echo "N: Don't install rustfmt"
-        echo ""
-        while true
-        do
-            echo -n "Install rustfmt? [y/N]: "; read yn < /dev/tty
-            case $yn in
-                [Yy]* ) install_rustfmt; break;;
-                [Nn]* | "" ) exit 2 >/dev/null 2>&1;;
-                * ) echo "Invalid input";;
-            esac
-        done
-    fi
-fi
-
-if [[ $verbose -eq 1 ]]; then
-    rustc -Vv && cargo -Vv
-    cargo fmt --version
-fi
-
-echo "--Checking style--"
-cargo fmt --all -- --color=always --check
-if test $? != 0; then
-    echo "--Checking style fail--"
-    echo "Please fix the above issues, either manually or by running: cargo fmt --all"
-
-    exit 1
-else
-    echo "--Checking style pass--"
-fi
+# Run
+check_cargo
+run_rustfmt