Store class/os/host/user overrides in the local repo config

Overrides are meant to be local to each system, unlike other
configurations which are often added to a user's dotfiles repository.

With this change, the configurations change names:

  alt.class => local.class
  alt.os    => local.os
  alt.host  => local.host
  alt.user  => local.user

test/106_accept_config.bats

@@ -129,3 +129,74 @@ setup() {
     return 1
   fi
 }
+
+@test "Command 'config' (local read)" {
+  echo "
+    When 'config' command is provided,
+      and an attribute is provided
+      and the attribute is configured
+      and the attribute is local.*
+    Fetch the value from the repo config
+    Report the requested value
+    Exit with 0
+  "
+
+  #; write local attributes
+  build_repo
+  for loption in class os host user; do
+    GIT_DIR="$T_DIR_REPO" git config "local.$loption" "custom_$loption"
+  done
+
+  #; run config
+  for loption in class os host user; do
+    run "${T_YADM_Y[@]}" config "local.$loption"
+    #; validate status and output
+    [ $status -eq 0 ]
+    if [ "$output" != "custom_$loption" ]; then
+      echo "ERROR: Incorrect value returned. Expected 'custom_$loption', got '$output'"
+      return 1
+    fi
+  done
+
+}
+
+@test "Command 'config' (local write)" {
+  echo "
+    When 'config' command is provided,
+      and an attribute is provided
+      and a value is provided
+      and the attribute is local.*
+    Report no output
+    Write the value to the repo config
+    Exit with 0
+  "
+
+  build_repo
+  local expected
+  local linecount
+  expected="[local]\n"
+  linecount=1
+  for loption in class os host user; do
+    #; update expected
+    expected="$expected\t$loption = custom_$loption\n"
+    ((linecount+=1))
+    #; write local attributes
+    run "${T_YADM_Y[@]}" config "local.$loption" "custom_$loption"
+
+    #; validate status and output
+    [ $status -eq 0 ]
+    [ "$output" = "" ]
+  done
+
+  #; validate data
+  local config
+  config=$(tail "-$linecount" "$T_DIR_REPO/config")
+  expected=$(echo -ne "$expected")
+  if [ "$config" != "$expected" ]; then
+    echo "ERROR: Config does not match expected"
+    echo -e "$config"
+    echo -e "EXPECTED:\n$expected"
+    return 1
+  fi
+
+}

test/108_accept_alt.bats

@@ -290,13 +290,13 @@ function test_alt() {
   echo "
     When the command 'alt' is provided
     and file matches only ##SYSTEM
-    after setting alt.os
+    after setting local.os
     Report the linking
     Verify correct file is linked
     Exit with 0
   "
 
-  git config --file="$T_YADM_CONFIG" alt.os custom_system
+  GIT_DIR="$T_DIR_REPO" git config local.os custom_system
   test_alt 'override_system' 'false' ''
 }
 
@@ -304,13 +304,13 @@ function test_alt() {
   echo "
     When the command 'alt' is provided
     and file matches only ##SYSTEM.HOST
-    after setting alt.host
+    after setting local.host
     Report the linking
     Verify correct file is linked
     Exit with 0
   "
 
-  git config --file="$T_YADM_CONFIG" alt.host custom_host
+  GIT_DIR="$T_DIR_REPO" git config local.host custom_host
   test_alt 'override_host' 'false' ''
 }
 
@@ -318,12 +318,12 @@ function test_alt() {
   echo "
     When the command 'alt' is provided
     and file matches only ##SYSTEM.HOST.USER
-    after setting alt.user
+    after setting local.user
     Report the linking
     Verify correct file is linked
     Exit with 0
   "
 
-  git config --file="$T_YADM_CONFIG" alt.user custom_user
+  GIT_DIR="$T_DIR_REPO" git config local.user custom_user
   test_alt 'override_user' 'false' ''
 }

test/111_accept_wildcard_alt.bats

@@ -74,7 +74,7 @@ function test_alt() {
     Exit with 0
   "
 
-  git config --file="$T_YADM_CONFIG" alt.class set_class
+  GIT_DIR="$T_DIR_REPO" git config local.class set_class
 
   for WILD_C in 'local' 'wild'; do
     local c_base="wild-class-$WILD_C"
@@ -118,7 +118,7 @@ function test_alt() {
     Exit with 0
   "
 
-  git config --file="$T_YADM_CONFIG" alt.class set_class
+  GIT_DIR="$T_DIR_REPO" git config local.class set_class
 
   for WILD_C in 'local' 'wild'; do
     local c_base="wild-class-system-$WILD_C"
@@ -170,7 +170,7 @@ function test_alt() {
     Exit with 0
   "
 
-  git config --file="$T_YADM_CONFIG" alt.class set_class
+  GIT_DIR="$T_DIR_REPO" git config local.class set_class
 
   for WILD_C in 'local' 'wild'; do
     local c_base="wild-class-system-host-$WILD_C"
@@ -199,7 +199,7 @@ function test_alt() {
     Exit with 0
   "
 
-  git config --file="$T_YADM_CONFIG" alt.class set_class
+  GIT_DIR="$T_DIR_REPO" git config local.class set_class
 
   for WILD_C in 'local' 'wild'; do
     local c_base="wild-class-system-host-user-$WILD_C"