Merge pull request #3198 from rrjjvv/var-typing-no-value-fix

Consider typed, value-less variables to have `null` value

bake/hcl_test.go

@@ -423,6 +423,63 @@ func TestHCLNullVariables(t *testing.T) {
 	require.Equal(t, ptrstr("bar"), c.Targets[0].Args["foo"])
 }
 
+func TestHCLTypedNullVariables(t *testing.T) {
+	types := []string{
+		"any",
+		"string", "number", "bool",
+		"list(string)", "set(string)", "map(string)",
+		"tuple([string])", "object({val: string})",
+	}
+	for _, varType := range types {
+		tName := fmt.Sprintf("variable typed %q with null default remains null", varType)
+		t.Run(tName, func(t *testing.T) {
+			dt := fmt.Sprintf(`
+	            variable "FOO" {
+	                type = %s
+	                default = null
+	            }
+	
+	            target "default" {
+	                args = {
+	                    foo = equal(FOO, null)
+	                }
+	            }`, varType)
+			c, err := ParseFile([]byte(dt), "docker-bake.hcl")
+			require.NoError(t, err)
+			require.Equal(t, 1, len(c.Targets))
+			require.Equal(t, "true", *c.Targets[0].Args["foo"])
+		})
+	}
+}
+
+func TestHCLTypedValuelessVariables(t *testing.T) {
+	types := []string{
+		"any",
+		"string", "number", "bool",
+		"list(string)", "set(string)", "map(string)",
+		"tuple([string])", "object({val: string})",
+	}
+	for _, varType := range types {
+		tName := fmt.Sprintf("variable typed %q with no default is null", varType)
+		t.Run(tName, func(t *testing.T) {
+			dt := fmt.Sprintf(`
+                variable "FOO" {
+                    type = %s
+                }
+
+                target "default" {
+                    args = {
+                        foo = equal(FOO, null)
+                    }
+                }`, varType)
+			c, err := ParseFile([]byte(dt), "docker-bake.hcl")
+			require.NoError(t, err)
+			require.Equal(t, 1, len(c.Targets))
+			require.Equal(t, "true", *c.Targets[0].Args["foo"])
+		})
+	}
+}
+
 func TestJSONNullVariables(t *testing.T) {
 	dt := []byte(`{
 		"variable": {
@@ -1565,6 +1622,20 @@ target "two" {
 	require.Equal(t, map[string]*string{"b": ptrstr("pre-jkl")}, c.Targets[1].Args)
 }
 
+func TestEmptyVariable(t *testing.T) {
+	dt := []byte(`
+	variable "FOO" {}
+	target "default" {
+	  args = {
+	    foo = equal(FOO, "")
+	  }
+	}`)
+	c, err := ParseFile(dt, "docker-bake.hcl")
+	require.NoError(t, err)
+	require.Equal(t, 1, len(c.Targets))
+	require.Equal(t, "true", *c.Targets[0].Args["foo"])
+}
+
 func TestEmptyVariableJSON(t *testing.T) {
 	dt := []byte(`{
 	  "variable": {
@@ -1877,19 +1948,6 @@ func TestTypedVarOverrides(t *testing.T) {
 			override:  `"hello"`,
 			wantValue: `"hello"`,
 		},
-		{
-			name:      "any",
-			varType:   "any",
-			override:  "[1,2]",
-			wantValue: "[1,2]",
-		},
-		{
-			name:         "any never convert to complex types",
-			varType:      "any",
-			override:     "[1,2]",
-			argValue:     "length(FOO)",
-			wantErrorMsg: "collection must be a list",
-		},
 		{
 			name:      "proper CSV list of strings",
 			varType:   "list(string)",
@@ -2090,19 +2148,6 @@ func TestTypedVarOverrides_JSON(t *testing.T) {
 			override:  `"hello"`,
 			wantValue: "hello",
 		},
-		{
-			name:      "any",
-			varType:   "any",
-			override:  "[1,2]",
-			wantValue: "[1,2]",
-		},
-		{
-			name:         "any never convert to complex types",
-			varType:      "any",
-			override:     "[1,2]",
-			argValue:     "length(FOO)",
-			wantErrorMsg: "collection must be a list",
-		},
 		{
 			name:      "list of strings",
 			varType:   "list(string)",
@@ -2313,6 +2358,7 @@ func TestJSONOverridePriority(t *testing.T) {
 		dt := []byte(`
             variable "foo" {
                 type = number
+                default = 101
             }
             
             target "default" {
@@ -2325,8 +2371,7 @@ func TestJSONOverridePriority(t *testing.T) {
 		c, err := ParseFile(dt, "docker-bake.hcl")
 		require.NoError(t, err)
 		require.Equal(t, 1, len(c.Targets))
-		// a variable with no value has always resulted in an empty string
-		require.Equal(t, "", *c.Targets[0].Args["bar"])
+		require.Equal(t, "101", *c.Targets[0].Args["bar"])
 
 		t.Setenv("foo_JSON", "42")
 		c, err = ParseFile(dt, "docker-bake.hcl")

bake/hclparser/hclparser.go

@@ -282,7 +282,7 @@ func (p *parser) resolveValue(ectx *hcl.EvalContext, name string) (err error) {
 	}
 
 	var diags hcl.Diagnostics
-	varType := cty.DynamicPseudoType
+	varType, typeSpecified := cty.DynamicPseudoType, false
 	def, ok := p.attrs[name]
 	if !ok {
 		vr, ok := p.vars[name]
@@ -295,12 +295,13 @@ func (p *parser) resolveValue(ectx *hcl.EvalContext, name string) (err error) {
 		if diags.HasErrors() {
 			return diags
 		}
+		typeSpecified = !varType.Equals(cty.DynamicPseudoType) || hcl.ExprAsKeyword(vr.Type) == "any"
 	}
 
 	if def == nil {
-		// lack of specified value is considered to have an empty string value,
-		// but any overrides get type checked
-		if _, ok, _ := p.valueHasOverride(name, false); !ok {
+		// Lack of specified value, when untyped is considered to have an empty string value.
+		// A typed variable with no value will result in (typed) nil.
+		if _, ok, _ := p.valueHasOverride(name, false); !ok && !typeSpecified {
 			vv := cty.StringVal("")
 			v = &vv
 			return
@@ -322,9 +323,6 @@ func (p *parser) resolveValue(ectx *hcl.EvalContext, name string) (err error) {
 		}
 	}
 
-	// Not entirely true... this doesn't differentiate between a user that specified 'any'
-	// and a user that specified nothing.  But the result is the same; both are treated as strings.
-	typeSpecified := !varType.Equals(cty.DynamicPseudoType)
 	envv, hasEnv, jsonEnv := p.valueHasOverride(name, typeSpecified)
 	_, isVar := p.vars[name]