From 251a4235a6eecb55a0911cbb5dfa2609aa260fd4 Mon Sep 17 00:00:00 2001
From: Marc Khouzam <marc.khouzam@ville.montreal.qc.ca>
Date: Mon, 6 May 2019 21:14:01 -0400
Subject: [PATCH 1/2] fix(completion): --flag=val breaks zsh completion

This is a bug I ran into when working on Helm completion.
I was surprised that it didn't happen when I was using
kubectl, so I investigated and found a PR that fixed this
bug in kubectl:
https://github.com/kubernetes/kubernetes/pull/48553

I duplicated the code in this commit which:

Removes __helm_declare, which is safe to do since
`declare -F` is already replaced to `whence -w` by
__helm_convert_bash_to_zsh().

The problem was that calling "declare" from inside a function
scopes the declaration to that function only.  So "declare"
should not be called through __helm_declare() but instead
directly.

To reproduce:
1- setup helm completion in zsh
2- helm --kubeconfig=$HOME/.kube/config statu<TAB>

you will get the error:
__helm_handle_flag:27: bad math expression: operand expected at end of string

Co-authored-by: Kazuki Suda <kazuki.suda@gmail.com>
Signed-off-by: Marc Khouzam <marc.khouzam@ville.montreal.qc.ca>
---
 cmd/helm/completion.go | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/cmd/helm/completion.go b/cmd/helm/completion.go
index 21d31d155..062451df6 100644
--- a/cmd/helm/completion.go
+++ b/cmd/helm/completion.go
@@ -126,13 +126,6 @@ __helm_compgen() {
 __helm_compopt() {
 	true # don't do anything. Not supported by bashcompinit in zsh
 }
-__helm_declare() {
-	if [ "$1" == "-F" ]; then
-		whence -w "$@"
-	else
-		builtin declare "$@"
-	fi
-}
 __helm_ltrim_colon_completions()
 {
 	if [[ "$1" == *:* && "$COMP_WORDBREAKS" == *:* ]]; then
@@ -210,7 +203,7 @@ __helm_convert_bash_to_zsh() {
 	-e "s/${LWORD}__ltrim_colon_completions${RWORD}/__helm_ltrim_colon_completions/g" \
 	-e "s/${LWORD}compgen${RWORD}/__helm_compgen/g" \
 	-e "s/${LWORD}compopt${RWORD}/__helm_compopt/g" \
-	-e "s/${LWORD}declare${RWORD}/__helm_declare/g" \
+	-e "s/${LWORD}declare${RWORD}/builtin declare/g" \
 	-e "s/\\\$(type${RWORD}/\$(__helm_type/g" \
 	-e 's/aliashash\["\(.\{1,\}\)"\]/aliashash[\1]/g' \
 	<<'BASH_COMPLETION_EOF'

From 8de22efd88060c41aa9a42abd8f3b8709e9309b8 Mon Sep 17 00:00:00 2001
From: Marc Khouzam <marc.khouzam@montreal.ca>
Date: Sat, 7 Sep 2019 19:09:05 -0400
Subject: [PATCH 2/2] feat(cli): Dynamic completion for global flags

Inspired greatly from kubectl code.
Completion is provided for:
--kube-context - where the available contexts are listed
--namespace    - where the namespaces of the cluster are listed

Signed-off-by: Marc Khouzam <marc.khouzam@montreal.ca>
---
 cmd/helm/root.go | 56 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 56 insertions(+)

diff --git a/cmd/helm/root.go b/cmd/helm/root.go
index cbda8273f..30b452fcb 100644
--- a/cmd/helm/root.go
+++ b/cmd/helm/root.go
@@ -55,6 +55,40 @@ __helm_override_flags()
         fi
     done
 }
+
+__helm_override_flags_to_kubectl_flags()
+{
+    # --kubeconfig, -n, --namespace stay the same for kubectl
+    # --kube-context becomes --context for kubectl
+    __helm_debug "${FUNCNAME[0]}: flags to convert: $1"
+    echo "$1" | sed s/kube-context/context/
+}
+
+__helm_get_contexts()
+{
+    __helm_debug "${FUNCNAME[0]}: c is $c words[c] is ${words[c]}"
+    local template out
+    template="{{ range .contexts  }}{{ .name }} {{ end }}"
+    if out=$(kubectl config -o template --template="${template}" view 2>/dev/null); then
+        COMPREPLY=( $( compgen -W "${out[*]}" -- "$cur" ) )
+    fi
+}
+
+__helm_get_namespaces()
+{
+    __helm_debug "${FUNCNAME[0]}: c is $c words[c] is ${words[c]}"
+    local template out
+    template="{{ range .items  }}{{ .metadata.name }} {{ end }}"
+
+    flags=$(__helm_override_flags_to_kubectl_flags "$(__helm_override_flags)")
+    __helm_debug "${FUNCNAME[0]}: override flags for kubectl are: $flags"
+
+    # Must use eval in case the flags contain a variable such as $HOME
+    if out=$(eval kubectl get ${flags} -o template --template=\"${template}\" namespace 2>/dev/null); then
+        COMPREPLY+=( $( compgen -W "${out[*]}" -- "$cur" ) )
+    fi
+}
+
 __helm_list_releases()
 {
 	__helm_debug "${FUNCNAME[0]}: c is $c words[c] is ${words[c]}"
@@ -105,6 +139,15 @@ __helm_custom_func()
 `
 )
 
+var (
+	// Mapping of global flags that can have dynamic completion and the
+	// completion function to be used.
+	bashCompletionFlags = map[string]string{
+		"namespace":    "__helm_get_namespaces",
+		"kube-context": "__helm_get_contexts",
+	}
+)
+
 var globalUsage = `The Kubernetes package manager
 
 Common actions for Helm:
@@ -196,6 +239,19 @@ func newRootCmd(actionConfig *action.Configuration, out io.Writer, args []string
 		newDocsCmd(out),
 	)
 
+	// Add annotation to flags for which we can generate completion choices
+	for name, completion := range bashCompletionFlags {
+		if cmd.Flag(name) != nil {
+			if cmd.Flag(name).Annotations == nil {
+				cmd.Flag(name).Annotations = map[string][]string{}
+			}
+			cmd.Flag(name).Annotations[cobra.BashCompCustom] = append(
+				cmd.Flag(name).Annotations[cobra.BashCompCustom],
+				completion,
+			)
+		}
+	}
+
 	// Add *experimental* subcommands
 	registryClient, err := registry.NewClient(
 		registry.ClientOptDebug(settings.Debug),